Has KDE fixed the inconsistent spacing in their default themes? In past eras every time I tried to use KDE the inconsistent spacing in the apps included with the desktop was jarring.
I really, really wanted to like KDE as it's super powerful otherwise.
There's certainly always a lot of effort going into that direction. The KDE community also has a goals voting process that elects multi-year community-wide goals (each goal gets their own leadership, funded hackathons, budget, etc.), and "Consistency" was one of the more recent batches and is still ongoing: https://community.kde.org/Goals/Consistency
So I'd say it's worth checking back, and certainly the developers/contributors take your ask seriously enough to vote for it themselves.
This is not to detract from XFCE, which is a cool project with many strengths as well, and certainly deserving of enthusiastic users (doesn't matter which FOSS desktop you love, we all win).