Most of that extra stuff is there to handle user contact privacy and security with the bridges, which is fair. I don't have any interest in self hosting beepers full setup, I want to get the functionality of multiple messaging services in one client - which I have, with my self-hosted matrix instance and the bridges they help develop and maintain.
I wish all of it was open source, but I did feel it necessary to head off comments that imply that the entire thing is closed source. Their implementation around dynamic servers and isolated containers spinning up isn't really the bit that seems relevant regarding user privacy with regards to data scraping or anything. There are a lot of comments in here implying it's fully proprietary, but there's a lot more nuance to it than that, as you point out.
Personally, I think it'd be nice if you could self-host just the bridge instances and connect them with beeper yourself, so that the part that isn't e2e encrypted is running on software you can validate and hardware you control.