Is there something I am missing, or does it really just come down to people not wanting software that isn’t “cutting edge” release?

It might just be that, people tend to gravitate to the next shiny new thing. But you're right, even when the application repos skew a bit older they're not really that old. And technically nothing is stopping you from running a more up-to-date application via flatpak, appimage, or just compiling directly. I think it's perfect for people looking for a more vanilla boring experience with the standard DE environments (GNOME, KDE, etc.).

I will say for total noobs another distro is maybe more friendlier, more polished installer, etc.. before settling on Debian I was happily using Ubuntu which felt easier for someone still getting used to Linux. But I always knew it was Debian based which made me curious about eventually just running Debian itself... nowadays Debian is my main and has been great.