If you want some of these features on mobile Android TV, you’ve still got options!
For Android TV, there’s SmartTubeNext: https://smarttubenext.com/ It includes ad blocking and SponsorBlock. I also think the UX is a bit better than the official YouTube app.
For Android, there’s obviously ReVanced: https://revanced.app/
And for iOS there’s uYou+ (hasn’t been updated in a while): https://github.com/qnblackcat/uYouPlus or iVanced (https://github.com/TherionRO/YouTubeiVanced) they will need AltStore to be installed, and will need to be re-signed with a PC/Mac every week.
You can also use AdGuard on iOS though safari and the SponsorBlock extension in the App Store too, but video quality isn’t great.
If you want to avoid resigning with AltStore or using Google services, there’s also Yattee for iOS: https://apps.apple.com/app/id1595136629 and Invidious and Piped client!
I don’t have an android device so if any of my info is wrong let me know!
Fixed, thanks!