Here you can talk about Apple's ecosystem, Apple's OSs (Operating Systems), Apple's apps, Apple's everything!!
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.
Brave browser also blocks YouTube ads. I'm not advocating for it over Orion (I'm using Orion + Ublock Origin & Sponsor block), but Brave also does work.
And Firefox Focus too!
Although that one might be a bit annoying for some users as it deletes the data after you exit.
Vinegar app/extension, then use the web version.
You can use Yattee ad an alternative client. It’s open-source and available for free on the AppStore.
Yes, but you don't get your logged in feed (or at least it was that way when I tried it). That was a deal breaker for me.
You can connect your Invidious account and watch your subscriptions that way. You can also subscribe to channels right from the app.