I'm not RanzigFettreduziert, and I don't know much about PopOS, but...

• Rolling release is awesome.
• Amazing documentation.
• Helpful user base. (The forums are great.)
• Does pretty much nothing that you don't specifically tell it to. (Like, very little is installed without your express say-so, for instance.)
• Customizeable as fuck.
• Doesn't making things harder by trying to hide the "hard parts" from you.
• Doesn't take days to install Libreoffice like Gentoo.
• AUR is great for software that isn't available in the official repos. (Always review the pkgbuild, but practically everything is there.)
• Very up-to-date (even cutting-edge) on everything.
• And surprisingly stable given how cutting edge it is. (That said, I've never run a keyword-unmasked system.)
• Definitely will teach you a lot.
• Very actively developed.

Downsides:

• Learning curve. (Definitely not as bad as, say, Gentoo, though.)
• You'd definitely have to get really comfortable with the command line. (Arguably as much a good thing as it is a downside.)
• The biggest exception to the "customizeable as fuck" bit is that you're stuck with SystemD, which is practically a whole OS. (And Artix (Arch but with a choice of init systems) is... kinda janky last I tried it.)
• Support for non-x86 (like ARM, for instance) is abysmal.

It's kindof the second-most hardcore OS out there after Gentoo. (Nobody actually uses LFS as a daily driver, so I'm not counting that for this.) It's the sort of OS that will teach you a lot and let you get down in the guts. But also avoids a lot of the downsides of Gentoo by remaining a binary OS.