I found some interesting live videos. However, I don't know how much data this platform uses. Is it as bad as YouTube or less? Mostly these are 2h streams.
It's similar to YouTube. It depends on the transmission quality.
Bad, no.
Similar to YouTube, yes.
Good videos need a lot of data, that's not bad, it's just a characteristic of it.
Both use state of the art compression. It doesn't get much better with video, that's not because they're particularly bad or something.