It is like saying that you should not have free speech because someone might influence 70+ to say stupid stuff (well, that is already happening...).
Family should be responsible on education or making phone of people that are not educated enough (minors, elderly, etc.) limited - I do that using Family Link. I have there my child and also my in-laws - both of them can't install new apps without my permission.
So the tech is already there, one just needs to use it.
What about an entire family of people who have no interest in learning technology they just want the shady ad-free youtube on their phone? I find it perplexing you've never met people like this. I'd wager it's more common than not in our world.
There is no way to have no "shady ad-free" on Google play. Have you tried installing anything that is free? Games for example? There are ads every few minutes that you either wait or accidentally click on them and you install another approved google play app, that has similar ads.
Look at apps on fdroid, no such thing.
So the solution is simple - ban google play and allow only fdroid if one wants good apps.
You can't protect everyone. Just like there are people oblivious to bad eating habits - it is a tax on ignorance.
Family should be responsible on education or making phone of people that are not educated enough (minors, elderly, etc.) limited - I do that using Family Link. I have there my child and also my in-laws - both of them can't install new apps without my permission.
So the tech is already there, one just needs to use it.