"OMG Riot, there's too many op champs I have to ban!"

it may be balanced but not necessarily good when everyone bans those champs because they hate them.

A healthier balance is when you don't want to ban anyone.

or it just means that there are too many champs that are frustrating to play against/that are too binary...

Then play one of those

When everyone is ban-worthy, no one is!

Bans should not be correlated to Balance. Bans should (ideally) exist when you don't want to deal with a certain Champion (like ) or when you don't want to deal with a certain meta (like ) they should not be there because the Balance Team isn't doing it's job properly (try banning every Jungler, I dare you. You can't, because there's not enough bans for that)

Poor Balance is when you use your bans against champions with high winrates or toxic gameplay. Healthy Balance is when you use your bans on champions you just don't like but have very reasonable counterplay.

Then what about the other 100+ champions? But its k cause u have diversity!!! The 15 lcsbigplays champions !!!

It's not a good thing when players feel that instead of counterpicking a champion they have to ban him, If you know that a champion is popular you might leave him open to pick a counter to him, if players feel that a ban is a better alternative means something is wrong with the overall balance

This is actually an interesting point that gets at the crux of "What exactly is balance"

You are describing the DoTA approach to balance. League tends to operate under the opposite assumption that "balance is weakness" - Zed