When I show them something on Youtube, the phone is always in my hands. They don't get to click on anything, I never give them unsupervised access to Youtube. Also, they're too young to even think about clicking those butts.

Regarding ads, yeah I use the Youtube app mostly because it's a better experience than watch on Firefox for Android or using Newpipe. I kinda wanted both to work, but the native app is so much better...