I’m assuming all these privacy forks are pretty much expected to be ai-free

Yeah ever since channels were added I am using that tab much lesser. And oh nobody texts me anymore either.

Where are the mods?

This is a very basic feature, you have a lot of options to choose from like the other comments have suggested. I use Heliboard personally with glide typing.

What do they achieve from this?

Block their Google account or block from viewing videos on YouTube?