I'm a huge fan of https://nextdns.io which works on iOS.

You can get ad blockers on Safari iOS. I think I have AdBlocker and Wipr. They don't work quite as well as a legitimate adblocker extension IMO, but I'm pretty sure they block a big number of ads and other garbage.

AdGuard works in Safari, and can block ads on youtube. I’ve been using this setup for years now and it’s been without problems. The experience is obviously not as good as the app, but it does what it’s supposed to, and I think the worse UX a plus because I do not spend as much time on the platform.

Brave browser has it built in, and there is a way to download an app to use specifically as an adblocker, though I forget how. I remember it not working very well, which is why I just gave up and use Brave instead.

AdGuard works in iOS Safari for free. (The Mac version is also good.)

(Although you should continue to pay for YouTube Premium. I do, it's well worth it.)