That is very annoying. There should be at least the possibility of "return to previous good old version"
Non-hypotetical example: Latest app update breaks in some weird way on older iPhones/iPads. While developers need to figure that out, users are left unable to use their apps.
Or worse, the developers get stuck in App Review Hell for over a week and are unable to release their fix to their users.
This happened to me when the reviewer took umbrage with our screenshots (which have passed numerous previous reviews) and kept rejecting our update. Meanwhile the app was bricked in some configurations with nothing anyone could do about it.
I had an app called gas cubby, which let me locally - on the phone - keep track of all my vehicles. I could enter detailed information about each car such as year, make, model, vin, insurance policy, gas purchases, oil changes and the like. It would tell you gas mileage and remind you of upcoming maintenance.
One day, the app was updated and all my local data was uploaded to the cloud.
Another app I had was camscanner from tencent that basically did the same thing. Think of all the PDFs you scan going to their cloud.
Another app that let you take a photo of a wine bottle and show you reviews of the wine. They added a social media login too. My list of favorite wines was gone unless I logged in.
I don't use those apps anymore.