I use Signtunes with uYouPlusExtra (on GitHub). This does not require a computer, but will cost you 10-15$ yearly to sideload without a computer. But Apple will allow sideloading SoonTM, so it might become free.
uYouPlus is no longer being actively developed, uYouPlusExtra is a fork under active development.
I came across this website thanks to someone sharing it here, so I thought I’d do the same: https://fmhy.pages.dev/storage/#youtube-frontends
I now use Waveform from Tracktion. Not open source, but all must have features are free. And supports linux, mac, and Windows.
However, if you’re used to Ableton Live, you’re probably better off using that. Good luck on your adventure pirate!
And for iOS I can recommend uYouPlus (https://github.com/qnblackcat/uYouPlus). The cheapest way to sideload it is using AltStore. But there are other services which offer sideloading on device, these don’t require a computer.
Also perfectly fine, I just prefer the features the uYouPlus app offers. It’s not only ad blocking, but also sponsor blocking, pop out player, background playback, reordering tabs (so I can remove the annoying shorts tab), and a bunch more.