Do you think there is a “best” most efficient programming language for building the program?
I think that depends on how important performance is for large instances, which I don’t really know. Python has a huge advantage due to being notoriously easy to get into, even for non-programmers. This means it can find contributors much more easily, leading to faster bugfixing and feature development. But Python is also slow, which might be an issue for large instances that have a lot of work to do.
In general, barrier of entry and performance act as trade-offs to each others. If you use a language with a lower barrier of entry, it tends too come with lower performance, and vice versa. So whether there’s an ideal language depends on whether performance matters and how much it does.
Creators can choose whether their videos should be accessible and whether they should be listed anywhere. Which you don’t seem to have ruled out being the case here. So I’d say you’re jumping the gun here.
I have seen channels which delisted (and later privated entirely) almost all their videos for legitimate reasons, so it’s certainly possible.
This one is almost certainly just delisted.
The fediverse has its own video platform (peertube).