Regardless of the frame rate, this video looks like an epileptic's nightmare. I prefer to work with well-synchronized signals, and then the frame rate is not so important.
I agree that it is always preferred to get a stable view of the rare event of interest, and with the powerful triggering options in modern scopes you can achieve that most of the time.
But before you set things up properly, you first need to realize that some unexpected signal is occurring. For me, the "Oops -- what was that little glitch on the screen?" has been the turning point of many eventually successful debugging sessions, sometimes identifying faults in areas where I had not expected them at all.
For that early "discovery" phase, I want a screen with fast updates, i.e. reasonably high frame rates. That's why I would not consider the Siglent web interface as my main UI at the bench (and I don't think it was meant to be that).