Then once they have done that, and these sites have lots of users and traction, mandate that Google, Facebook etc also federate using ActivityPub. If they don't, block their sites.
(which happens to be the real world)
I very much doubt this is the case given the number of tariffs with data caps
As anecdata, I cut my package back to 5GB at the start of the first lockdown as my mobil data usage went to nearly 0 since wifi at home and did not run out of data during the last year. I assume anybody who was able to do that done the same.
If "for most is unlimited" you mean "most don't use up all their data", then yes. If you mean "most have unlimited data plans", then see links above.
EDIT: apologies for the statista link, it wasn't paywalling me when I first looked: it shows about 12% have unlimited data.
There's currently no way to horizontally scale an instance, so after an instance grows past a certain size it can't transcode uploaded videos fast enough. I love the project but if it can't utilize multiple compute instances to transcode video (or plug into a cloud platforms video transcoding offering), it's never going to grow past this blocker.
However I also acknowledge the authors are very open to ideas and they are really awesome. I guess some wizards who knows scaling related things need to be hired and it will costs a lot of money. AFAIK peertube generates money from donation so I don't think we should be harsh on them.
I wasn't aware of that -- fixing it would be a very necessary improvement to the codebase to make the software more useful on big sites.
I've never actually watched a video on a mobile device (I tried once and didn't have enough bandwidth).
If I'm at home or office, I have a desktop PC, and if I'm out and about I have better things to be doing with my time.