Am I missing something? In my experience using Obtainium it pulls apks from sources I tell it to, usually the developers git releases and even sometimes f-droid repos. This app doesn't compile anything.
The main benefit is watching for updates directly from developers which, again in my experience, has been quicker than waiting on f-droid. You could even have it do just the notification and you can manually go download and install if you're the cautious.
The developer of obtainium or the packages we're installing? I'll assume the former. If you're skeptical about obtainium you could still use it as a source to monitor && notify and then do your install manually.