I feel like there's a poor buffering algorithm involved. It was a bit choppy for me even though the playback bar indicated that the video had loaded well ahead of time.
Downloading that video with wget took me 0.4 seconds.
Connecting to peertube.tv (peertube.tv)|77.168.118.55|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1058937 (1.0M) [video/mp4]
Saving to: ‘de5a56e4-036c-4536-b1a6-4ac45b872516-576.mp4’
de5a56e4-036c-4536- 100%[===================>] 1.01M 2.79MB/s in 0.4s