>But it mostly didn’t, it was generally good enough, and when it did it commonly pointed to a bug in the app anyway

That hasn't changed though? The individual settings might have changed. Some were added and some were taken away, as is usual in development.

>The look and feel are both completely different from Windows 10 and 11 overlay scrollbars, and you certainly can’t accurately emulate the behaviour and I doubt you can emulate the look either.

If there are subtle things then no you probably can't without writing a new widget. So again, you're talking about having a big #ifdef inside the scrollbar code. Practically speaking the maintainers would then have to maintain at least two separate scrollbar implementations. Those are the Windows 11 scrollbars though, what about the old Win32 scrollbars that are still used in a lot of places? Do you skin them to look and act like Windows 11? 10? 8? Vista? Do you change that at runtime by detecting the OS version? Just looking at the scrollbars on my Win 11 install I see at least 4 different scrollbar styles. So which ones do you support?

Say you decide to go the easy route and only support the default Windows 11 scrollbars with the overlay. Fine. They won't look right if you run them on Windows 10 or 8 but whatever. So when when Microsoft releases a new version or changes the behaviour of the scrollbars, you still have to track that and release a new version in step with Microsoft so it doesn't get out of date. If you want everything to be consistent then you have to do it with every widget, not just scrollbars. That's easily several full time jobs just doing that, which no one has been available to do. Because realistically you need people who are expert Windows developers as well as expert GTK developers, and they have to be willing to volunteer to work for free full time because GTK is a volunteer project. As far as I've seen those people just don't exist.

Really though, I don't think it's as big a problem as you're making it out to be since Windows apps are already widely inconsistent with regard to every widget, including scrollbars.

>macOS lets you turn overlay scrollbars on or off at the user level.

Compared to the work of reimplementing everything, it's not particularly hard to push another boolean setting through the code. It's already there on the app level. But like you say, that wouldn't really solve anything.

>they’ve been actively and deliberately gutting stuff useful for other platforms, and refusing to undelete things because of their vision of how things should be

Every project has a vision of how things should be. That's what separates every project from the rest. That isn't why this is happening though; most of the time they're refusing to undelete things because no one is around to maintain them. You don't just bring code back into the project and suddenly it works, someone has to do actual work to make that happen. If you can make a real good case for bringing back that code, and you can show you'll do the work and you won't disappear, then that person could be you. Currently I don't think any maintainers are Windows developers, they're just trying to keep roughly the same amount of Windows functionality working within the time they have available to work on it. Which is not a lot of time.

But I can see you've already made up your mind that the developers are trying to make things worse for you and sabotage you because they don't like you or something, so I doubt I can convince you of anything. This is why I don't enjoy engaging with this forum often. Have a good one.