For me, it was perhaps simple-scan, a very simple and efficient GUI to scan documents. I used it with my Brother printer / scanner and it works like a charm. Especially since I do not scan stuff often, so a program with more complex UI would have the effect that I forget how to use it until the next time.
Only works on Ubuntu though last I heard (and not even downstream distros), which is somewhat unfortunate
You’re right. But I’d rather have limited Linux options than no option at all.