Do they record every talk? I can't find many talks from 2022 so it seems unlikely.
I'm dumping streams for a few of the rooms I care about, might upload them on Youtube later
And in the case of youtube they make significant effort to maximize accessibility when it comes to devices being able to successfully play the videos and get the message, as it aligns with their need to show ads to as many people as possible.
I'd argue shoving informational content on youtube is making less a deal with the devil than say hosting your FOSS projects on github...
(If you have usable FOSS Youtube alternatives, don't mind trying to use them)
Peertube is well suited for events like FOSDEM. The CCC use https://c3voc.de/wiki/voctomix but a littler harder to use.
They do interact a bit, to make it seem more seamless.