Can I remove KDE?

Yes. You can. It won’t break anything. Try this:

erlangen:~ # zypper --non-interactive remove --dry-run --clean-deps --type pattern kde
Reading installed packages...
Resolving package dependencies...

The following 30 packages are going to be REMOVED:
  ark ark-lang gwenview5 gwenview5-lang kate kate-lang kate-plugins kcalc kcalc-lang kipi-plugins kipi-plugins-lang libKF5JSApi5 libKF5Kipi32_0_0 libKF5MediaWiki5 libcfitsio10 libdjvulibre21 libgnustep-base1_29 libkColorPicker0
  libkImageAnnotator0 libkerfuffle23 libkipi-data libobjc4 okular okular-lang patterns-kde-kde skanlite skanlite-lang spectacle spectacle-lang unar

The following pattern is going to be REMOVED:
  kde

30 packages to remove.
After the operation, 107.0 MiB will be freed.
Continue? [y/n/v/...? shows all options] (y): y
erlangen:~ # 

More patterns are lurking:

erlangen:~ # zypper se --type pattern -is kde
Loading repository data...
Reading installed packages...

S  | Name       | Type    | Version      | Arch   | Repository
---+------------+---------+--------------+--------+-----------------------
i+ | kde        | pattern | 20230403-1.1 | noarch | Haupt-Repository (OSS)
i  | kde_pim    | pattern | 20230403-1.1 | noarch | Haupt-Repository (OSS)
i  | kde_plasma | pattern | 20230403-1.1 | noarch | Haupt-Repository (OSS)
erlangen:~ # 

Removal in the above patterns may result in unneeded packages. Remove them too: Cleanup of distribution upgrades

KDE is neither buggy nor bloated, in my opinion of course. You may try and revise your opinion.