It’s very nice to not have a dozen different versions of the same distro to parse through and figure out that are simply the same distro with a different DE. Moreover, very few of them offer this many options.
Cachy could be doing a better job explaining what the user is looking at here and who each of these is for. Pretty easy to sum up in 1-2 sentences…
when you install a DE as part of system setup it’s usually preconfigured by the distro maintainers. otherwise you need to do that configuration yourself, which is more difficult.