Ubuntu. Pretty sure you already have an idea why. Lol.
OpenSUSE. I've always had issues trying to use it, from zypper to updates to bootloops. It's also sluggish compared to other distros (yes, same DEs usually) on my laptop. I've tried at least 3x trying to get why a lot of people love it. It's just not for me.
I've never tried Manjaro yet, but coming from Arch and EOS I don't think I ever will.
You're right. The devs know it can be confusing to new guys and are planning to do something about it. Idk what the progress is, though. They seem to be pretty busy making lemmy stable first.