Yeah, that's pretty much it. They standardized on 24 back when sound on film took over Hollywood, and we now have a century of film shot at that speed. It's what "the movies" look like. There have been a few attempts to introduce higher frame rates, like Peter Jackson's The Hobbit and James Cameron's Avatar, both at 48 fps, but audiences by and large don't seem to like the higher frame rates. It doesn’t help that we have nearly a century of NTSC TV at ~60 fps[1], and our cultural memory equates these frame rates with live tv or the "soaps," not the prestige of movies.
[1]Technically 29.97fps but the interlacing gives 59.94 fields per second.
In my experience, just fine. I recently ran a large (~30k) marathon and my AirPods and watch never glitched once, streaming the whole time including in the packed start corrals. I had the same thought about RF contention, but Bluetooth didn't seem to care.
I think the poster is referring to "Brand Indicators for Message Identification[1]". A new(ish) protocol to display branded avatars for messages in email clients.
[1]Technically 29.97fps but the interlacing gives 59.94 fields per second.