I think the conflict comes from the philosophical opposition to the application being in control of such a thing. Title bars are for window management and application termination, which are beyond the purview of the application itself. GNOME decided that they wanted it to be something different and include application controls as well all on their own.

Interesting, I was not aware of libdecor. Sorry to hear that it degraded your experience - it really sucks when things like that happen. For what it's worth, I have seen some interesting themes which could be a reasonable solution to that problem - basically, they made the titlebar very thin or completely missing, except in the area where the window buttons were located, which were enlarged. Not sure which window manager they were made for though - I think it was either xfwm or openbox.

But in any case, this is the problem with CSD - it doesn't really have a complete, holistic vision. It's great that they're trying to be innovative, but then they very quickly run into problems like the one described by the Factorio developer above. So now they're in a very awkward position that simply cannot meet everyone's needs.

And yet, we never had this problem before they went on their quixotic CSD journey - that's why many people think it was a really bad idea.