On the conflicts of the old lore and the possibilities of the new
When the focus of your story is the Institute of War, an organization that prevents war, and your regional plot hooks mostly involve regions threatening to explode with war that can spill out and consume the rest of the continent, there is a problem because inherently, the strength of one of these will sideline the other. To the extent that the Institute is relevant to the story, the war cannot be and visa-versa.
When your other major hooks involve local conflict within regions, which the organization has no mechanism for involvement, that is also a problem. To the extent one is focused on, the other stands to be sidelined. Jynx and Vi are both Piltover champion in the League. Presumably then if there’s a League issue their differences get sidelined. If they’re not getting sidelined, then a League issue can’t be the focus unless it’s the focus in how the antagonistic relationship can hurt Piltover in the League, but with so many Piltover champions that do get along, this sort of plotline has problems of its own. In all of these conflicts, neither party has standing to call a judgement against the other, so by definition, any resolution or even exploration of them would specifically occur outside the Institute and the League.
This is the problem with the old lore, which isn’t a problem with the lore itself. It's an incompatibility between the setting as it is and the stories Riot wants to tell. It may also be an incompatibility with the stories players want to see. It's not a problem intrinsic to the League.
For example: It might be great to think about the Demacia-Noxus conflicts, but what are their options for an actual conflict? They're city states, so there's not too back and forth over territory they can do. Theoretically, either can just have a judgement with the other to conqueror the other, but what would that mean for the loser's champions' standing in the League? If Noxus wins do they just all become Noxian champions? Do they become independent ones? Would they be able to just challenge Noxus back? Unless a lot of those answers fall along the League judgement’s result being very limited in scope, that’s the end of the Noxus-Demacia conflict.
Or, here's the big one, what happens if, say, Demacia wins and Noxus refuses to accept the outcome and turns to conventional war? Is the Institute of War strong enough to stop them? Either answer is full of headaches. In the old lore, The Institute destroyed one of their largest nexuses (nexi?) to freeze the battle happening in Kalamanda. That suggests they can't just throw that magic around each time. How well could they stop an all-out war with multiple battlefronts without damaging their ability to respond to anything again? But then what about the nexi (nexuses?) that get destroyed at the end of every judgement? And then...well, you get the idea by now, I'm sure.
Note that each of these problems have the potential for very interesting stories within the current lore to resolve them. The only problem with this is any story answering one of these questions stands to answer a whole lot more of them, and by its nature, it’s only a story that can really be told once.
These are large, significant issues that have no easy resolution in the current lore because the lore, in a way, is set against itself.
There are a number of lesser ancillary problems that can be solved individually that a clean slate can address in one fell swoop too.
You have issues with certain champions whose only role is really to be confined by the Institute. Sure,
is a great champion, but what can you do with him? Nothing really. And champions like him and
have been given lores that make them so powerful that they can't have any meaningful stories outside the League. If the League isn't restraining them, they're by all accounts unstoppable. You can remake them, but what do you remake them into when their identity it tied so so tightly to the Institute?
How exactly is the field level between Jayce, Mr. Square Jaw with a hammer, and Fiddlesticks, an enigma who murders anyone who enters his room, even summoners, in seconds when they enter a judgement?
If summoners are so powerful, how do they end up the redshirts in every story showing how powerful something is only to have this thing regularly go on to fight on equal terms with other champions?
What happens when Cho'Gath grows really large in a judgement and the judgement ends?
When the lore talks about certain independent champions like Jax and Sivr being in high demand, what do they mean when the only people who can issue judgements are countries with a large staple of champions?
That's just a sample, and that's also just of the top of my head.
These problems were likely caused by lore being added on bit by bit without sufficient consideration or regard to the whole of the world or the lore's implications. The benefit of regarding nothing as sacred and rebuilding everything is you get to do away with opposing or contradicting elements and create a setting that fecilitates the stories you hope to tell. That means having a setting where Demacia and Noxus can have meaningful conflicts without having to rewrite the setting each time they do. It means having a lore that can address Syndra's antagonism with the rest of Ionia in a meaningful way as well that doesn’t ignore what is supposed to be the very heart of the lore in the world.
Are these problems with no other way to address them? Of course not. I'm sure you can find loads of fanfiction with a variety of different fixes. To a certain extent, a lot of these issues had to be addressed to tell certain stories, which is why you see so many different interpretations. I myself imagined the Institute as something that allowed petty grievances that would never have gone to conventional war to balloon into judgements. This, in turn, led to judgements becoming a tool for political and diplomatic maneuvering. (Surprising precisely 0 of the the players in the campaigns I DM) For example, did a visiting dignitary offend an influential figure and refuse to apologize? A judgement to force an apology might happen. While this works for signatory nations, this fact also threatened the Institute’s irrelevance when it came to greater matters. I have the luxury of not having to have the Institute or the League at the heart of my stories, though. Also, no matter what solutions there are, they’re solutions because these things are problems, and they need to be addressed somehow.
Is this approach problem-free? Of course not. No approach would be, and I can write the length I've already written about the possible pitfalls. It does prevent them from having to keep going back and patching old bits that, upon consideration, weren't properly crafted to handle a large roster of Champions in a world filled with interesting conflicts, though.
For example, it can give us a landscape where certain Champions have the ability to link with other champions and create a metaphysical battlefield over mutually agreed upon terms, where regular soldiers entering the field become represented by nothing but minions, nexi are the focus of the spell holding the battlefield together and results are binding by magical contract. There you have a setup that can but battle at the heart of smaller conflicts, make for uneasy alliances. have battles between countries that are necessarily of smaller scale and don’t obviate the utility or need for standing armies. With a bit of tweaking you can probably come up with a mechanism that can make champions force battles on their terms, meaning larger armies won’t necessarily obviate champions either. You can even come up with a place for a League, perhaps enshrined by eternal forces that are the source of these abilities. It would also create a system that explains the need for uneasy alliances of different shapes. It also answers why every member of the League is a member. They have the ability to be, making them extraordinarily rare and extraordinarily useful.
This isn’t a submission for a perfect idea that would fix everything. It’s an example of how breaking everything down can better create a setting that encourages certain stories in greater volume instead of getting in the way, and in the end, I think that’s what Riot’s trying to do.
P.S. Riot feel free to crib any of this. Payment by RP would be appreciated compensation. Hiring me onto your lore team, though, would be preferred. :P