There are two ways to do it. The first is to use iOS content blockers that you get from the App Store. At a minimum you’ll want AdGuard. I also use Baking Soda, Banish, Extract, Vinegar, and StopTheMadness. (Yes those are all apps.)

If you want to go the free-ish route you can use the Orion browser, from the App Store, which then allows you to use Firefox plugins.

Either way, you can and should delete the YouTube app and watch through your browser after installing whichever filters you choose.

It’s like the seasons in Texas. You have summer, MEGASUMMER, still summer, mostly summer but with rain.