It deserves mentioning that Firefox on Android supports extensions, so if you uninstall/disable the official YouTube app then add uBlock Origin and Sponsorblock you get a more tolerable experience.
Or just use Revanced or Grayjay, both of which are ad free and support sponsor block. Revanced is still a bit more feature complete imo, but also more buggy on my device, and more of a hassle to update. The browser YouTube experience is so bad, ads or ad free.
Can also use Vinegar (for YouTube) and Baking Soda (for basically every other site with videos) with Safari on iOS. It’s not a perfect solution, but it at least revamps Safari’s built-in video player so watching in the browser is actually tolerable.
You can also patch YouTube in a similar way as revanced on iOS, I use YTLitePlus. And for Adblock I use the Wipr extension and hush for blocking and auto rejecting cookie popups.
No jailbreak needed.