I think clarity is the wrong word for what you're talking about. You seem to be complaining more about general design, not about the elements of visual.
If you want a specific example, Wukong was originally going to be a much more complex and interesting champion, but was scrapped cus he was too hard.
That isn't a clarity issue. Clarity is the accurate conveyance of information, not the actual complexity of the information itself. Clarity would be "we put a particle on enemies hit by Wukong's Q so you know there's an armor shred on you". It is not "we redesigned Wukong's Q because we thought it was too hard to use right". That's a design issue. Clarity only accurately conveys design.
Clarity answers the question of "can I tell when the spell is being aimed at me?", not the question of "what is that spell aimed at me going to do?". It's much more related to visual design than it is actual game design. It is just a description of how well information is conveyed. If I can't tell what a spell is doing by looking at the visuals, the visuals have poor clarity. If I can, they have high clarity. There isn't really anything more to it than that.
You may or may not have a legitimate complaint that Riot hasn't produced complicated and unique designs, and/or that they're dumbing down the game, but you're using the wrong term to describe it. You could talk about oversimplicity or counterplay or "burden of knowledge" (a previous Riot buzzword that is actually related to the concept you're describing), but clarity just is not the right word. I'd complain about clarity if they changed the particles of a spell so it looked confusing. I wouldn't complain about clarity at all if they redesigned the spell entirely because they thought it was unfair or weird.
Dota has actually been on a pretty big spree of increasing clarity a lot lately. They actually had a developer post maybe a year or so ago explaining how it was a goal for them going forward. They redid the descriptions of their damage system to make it more clear how abilities would interact. They've added particles and animations to previously invisible spells and casts. They've changed abilities that previously looked very similar. They redid Shadow Fiend's model and gave each different Raze a different cast animation. That's what clarity is. It's a good thing for a game. Conveying information accurately is not a bad thing.
If you're not talking about conveying information accurately, you aren't talking about clarity. If you use a different term, people will be much more likely to understand what you are trying to say.
We get a random floating blob instead of a ghost wolf that fits more thematically.
Did Riot ever actually give this as a reason? I've seen people claim this was Riot's goal, but I've never seen them actually say it. I thought it was because the ghost wolf idea looked kind of.... well, I don't have any polite words to describe it. The blob isn't really any worse than that thing.
