Re: To be honest
Particularly in GTK land, where the GNOME people have decided that even windows decorations should be the domain of the apps, so they can decide what borders and min/max/close/etc buttons are there and how they should look and act.
I actually really like themes, but from the KDE side of things, where a theme is what you set in your desktop environment's settings and then *all applications* display accordingly. That's the KDE way; sane defaults, and lots of customization available but centralized so that there's cohesion. And then a GTK or even worse an outright GNOME app will waltz into my life and ruin it all (although the ability to set matching GTK themes in KDE's System Settings is somewhat of a panacea).
But yeah it really is shocking how much is done to make applications break away from a desktop environment's look & feel. Adobe is particularly atrocious for this, where their various products, and launchers for their products, and installers for their launchers for their products, seem to aim for as much heterogenity as possible and completely ignore the desktop OS they're targeted at. I mean it's honestly not very hard to make your application look native to Windows when it's running on Windows, native to macOS when it's running there, etc etc, but so many companies deliberately do the exact opposite, and then keep changing their minds so there isn't even uniformity across their *own* software interfaces.