GNOME and KDE are the MAIN Desktop-Environments of the GNU/Linux ecosystem and they have been arround for a LONG time.
imo it’s not wrong for people to keep BOTH installed and keep an eye out for each and report bugs if they CAN.
the CLI is way more powerfull but not everybody want’s to invest time in learning it nor is it a MUST nowadays.
from what i have seen developers and people who CONTRIBUTE to these two DEs tend to “borrow” the things which are good from one and implement them in the other … this is the beauty of the GPL. if you see something worth having in one of them you can bring it yourself in the other.
as such - even if they look different by default people who know how to customise them can probably bring them to resemble each other very closely. it might not be a perfect resemblence but for those that complain that GNOME is too touch friendly on the desktop side out-of-the-box they can massage it a little and voila you have a perfectly usable desktop. the same can be said for KDE/Plasma on the mobile side, though i suspect it needs a little more love to be at the same level on the L5 hardware.
other than that, they are both usable and highly configurable if you massage them ENOUGH to get what YOU want out of each.
i’m quite a fan of the vannila GNOME theming/icon-set from 3.36.
popOS uses the too light blue color and in the Disks front-end this has a nasty side-effect of making the partitions not lisible ENOUGH … i’ve switched to ADWAITA the first chance i got during my testing period …
Fedora and Debian Testing BOTH did EXTREMLY WELL imho with choosing to go VANILLA GNOME. 