I’m surprised Apple’s system (or lack thereof) for app testing has lasted this long without a major overhaul. At some point it seems like Apple has to acquire TestFlight or build their own version.
As Jessica Vascellaro points out, the developer test account system was sort of arbitrarily set up:
Apple picked 100 believing it was a big enough sample for most companies, but still easy enough for it to manage, according to a person familiar with the matter.
Most developers I work with seem to use TestFlight now. But increasingly I’m seeing people simply pushing their apps live into the App Store and offer some sort of code to testers to activate the app’s service. In other words, there are apps in the App Store which do nothing for 99.9% of users. That seems like a poor solution and experience.
Others do buy more developer accounts to open up testing to more users, but that still requires UDID sharing which is something most users will never be really understand.