Riot is not the only big company to cock up gameplay this badly. Several others also became mediocre
There's been a great deal of negativity these days surrounding League and its gameplay and many people are just straight up not playing anymore. It's ironic though, because other developers that have cocked things up, like Riot is doing right now, are still around, still making mistakes. Riot could easily learn from them, but they prefer to work in a vacuum, so they can hear their own thoughts better. Criticism just makes things needlessly complicated, doesn't it? Recently, Riot’s attitude towards League’s gameplay has been thus: only take action if there is no other choice, AKA when the negativity surrounding a certain aspect of the game is simply too high. All other problems can wait half a year to be addressed or even acknowledged. Other developers have adopted this behavior in the past too. Despite the success and fame they’ve enjoyed, these developers have allowed the arrogance and hubris that comes with that success to harm them irreparably.
Remember Bungie? Yeah. Halo was an FPS series that defined an entire decade. Now, they make Destiny, a franchise that was supposed to define the next decade, but instead is a joke that constantly pesters you for money (search hidden XP reduction and the Eververse as examples). Every time a player discovers yet another "feature" that attempts to coerce them into spending cash, Bungie has to reply with a poorly constructed PR statement, followed by removing said feature. On top of that, Destiny 2's core gameplay has no depth, substance or replayability, especially compared to the final version of Destiny 1. Sound familiar?
Remember Bioware? They made a name for themselves as THE developers to go to for great single player narratives in game. They were the BEST at it. How many people still think that? From Mass Effect and Dragon Age: Origins, they end up creating Andromeda My face is tired. and now Anthem (which looks suspiciously like a Destiny clone). Bioware seems to be giving it their all with Anthem, if the trailers and E3 are any indication, but their fans are unlikely to come back. They've made too many unfixable mistakes and also, they've opted to make Anthem a multiplayer game, instead of a single player narrative, which is what they used to be famous for. What are they famous for today?
Have these companies lost all their fans? Of course not, but they are sure as hell nowhere near as popular as they used to be. Their next games HAVE to be home runs if they want to win back their good reputation. Anthem HAS to be a home run and whatever game Bungie makes next now that they've left Activision HAS to be a home run, which is unlikely, given their recent track record.
The other example needs to be looked at from a different angle because it’s a game, not a whole company, but remember WoW? That game had such a massive effect on the game industry that it caused a ton of clones and imitators to crop up for years. Yeah, just like League did. Obviously, Blizzard is doing fine at the moment, but that’s because they have three other franchises to fall back on, four if you count HotS. So how are WoW’s subscriber numbers now? Not sure, Blizzard doesn't release that data anymore, possibly because it makes their shareholders uncomfortable to see it’s still declining. However, their last report in 2015 showed 5.5 million subscribers. Which is only 6.5 million short of their 12 million peak in 2010 (which is roughly the population of Moscow. Random fact, enjoy). They've been trying to recapture that peak ever since. Which is a shame. Because it's been about 8 years too late since the decline started (when Cataclysm was released and their subscriber count started to drop).
Just like Riot, all of these guys were giants in the game industry. All of them lost players when they introduced things that were not welcome or caused players to lose interest. All of them are currently trying to recapture their peak. Riot isn't quite at that point yet, which means they can still reverse course. Unfortunately, the first step in solving a problem is to acknowledge that there is one. Riot is, famously, quite averse to doing this.
Do I think Riot will go bankrupt? Obviously not. Just like Bioware and Bungie haven't and WoW hasn't died yet. But if they continue to lose players to Fortnite, they won't get them back, because when players leave, they tend to leave for good. I said that Bungie and Bioware need a home run in order to pull themselves back up. I give them much better odds than Riot (once League gets bad enough) because it's easier to market and generate hype in the game industry around a brand new IP. It's not easy to generate hype around patches and seasons, because the only people who look at that stuff are usually playing the game already, the rest have to be reacquired by word of mouth. Unfortunately, like I said before, given the attitude Riot has adopted, they will only take action when they have to. Once there's a decline in player population, Riot can try all they like to pretty up the game, add in flashy new features, more champions, but those people aren't coming back to League. If you burn someone, don't expect them to come running back if you’re still holding the torch. Today, Bungie is mediocre. Bioware is mediocre. WoW is mediocre. Just like them, Riot can easily become mediocre too, even though they were once great.
What’s my point? Be ready to look at Riot in the future the same way you look at Bungie, Bioware and WoW. They are just as likely as those three to become average. Being big now doesn’t protect you from jack in the future, especially if the problem is your own ineptitude.