Understanding manaless champions
Riot does not do anything as a sort of "perfect science" or whatever. I don't know what that will look like but It means the pattern may break so to speak
but look at any given resource or lack therof and you will find certain weaknesses
I will skip mana champions as there are a lot of these
But then there are resourceless champions and energy champions etc.
Of course those with any resource at all are going to be treated differently than completely resourceless but there's a price to be paid regardless.
But now I'm going to just focus on resourceless because they are the easiest to understand and from them you can derive how the others work.
resourceless champions (they have nothing to actively spend per se)

these are the only 4 with nothing whatsoever to manage aside from cooldowns. You'll probably notice that these are much older designs than most.

these have nothing to spend but have something to use or lose to either decay or damage or whatever.
I'll start by saying that riven should, for the most part, be considered her own category, she is an old design and tends to almost be an exception though she really isn't.
Now, notice how the first three are actually kindof bad pushers. Very bad in fact but they all can eventually push a lane if they pour cooldowns into it. But all 3 have either an execute or just something to clean up with. All three have sub par CC abilities, all 3 are melee with some sort of damage resistance ability. All 3 tend to have a rough time teamfighting phase when they try to be aggressive on their own for the most part though they all have their moments and must still be taken seriously. Mostly because of short range. Riven does have a long range execute.
Something they have in common with group 2 is that they are all also only slightly mobile or even nonmoble unless a certain condition is met. Garen even gets slowed under some conditions.
These champs when played effectively will typically need to focus on engaging the enemy. Even garen has a very slow acting passive heal that discourages engages but encourages the enemy to engage him regardless. In a sense this also encourages engagement if he is staying in experience range of minions or whatever.
But then we have stuff like energy champs

these champs often need 2 abilities up to really fight you and aren't the best lane pushers unless they want to waste resources. They also lose more by playing passively than they do by playing aggressively energywise. They tend to have erratic but existing windows of opportunities to counterplay but you must learn when this is for each one. when their ult is down it tends to be a green light for dealing with them. akali with less than 3 ult charges is not exactly the biggest threat on the rift even.
Again none of these are very good pushers. Zed kindof can... but not that well and he needs his whole kit to do so effectively. They all farm a bit better than the complete manaless champs but all either struggle to cs in extreme situations like under tower or in teamfights or they just can't push a lane to save their lives without itemizing for it.
Look for more patterns. You will notice that there are patterns in when the manaless champ was released vs what their weakness is too
