It’s even worse for developers… sometimes you push out an app for internal or extenal test and it just… sits there… the users continue to see the old one. Or half of them get the new one and half get the old one, which makes no sense. This has been an issue for years with nothing but shrugs from google when you ask them about it.
OTOH with testflight you push out a build and 20 minutes later all testers get it, automatically, every time (I hate iOS development generally but that bit they got right).