Yes because for example I'm sticking to K9 mail 5.6 because of the UI change in the next versions. I picked K9 exactly because of the original UI so I'm not using the new one, which is like every other mail client. I saved the APK and I'm installing on any device of mine, also when my fingers slip on the update button. Uninstall and install 5.6 from the file manager.
And no, because if the company behind the app wants to force people to upgrade they'll make the backend incompatible with the old app. Also no, because I don't think that many normal people invest time not upgrading an app because of the UI.
Yes because for example I'm sticking to K9 mail 5.6 because of the UI change in the next versions. I picked K9 exactly because of the original UI so I'm not using the new one, which is like every other mail client. I saved the APK and I'm installing on any device of mine, also when my fingers slip on the update button. Uninstall and install 5.6 from the file manager.
And no, because if the company behind the app wants to force people to upgrade they'll make the backend incompatible with the old app. Also no, because I don't think that many normal people invest time not upgrading an app because of the UI.