As one frog said to the other frog: it's only a couple of degrees warmer! What's the problem?

Again, this is a new piece of software. It does not affect existing login managers (eg SDDM) and nor does it affect KDE Plasma itself.

The approach the KDE team took here is 100% the correct approach and, crucially, does not affect Plasma’s cross platform support at all.

This whole thing has been blown out of proportion by armchair critics commenting with made up hypotheticals without any of them reading what the actual change was. It’s ridiculous

It's a minor temperature increase, but I believe that KDE quite explicitly does not intend to boil that frog.