Nice. Actually some of these remind me of Windows, too. It's less common on Windows but plenty of applications seem to link against antiquated libraries which provide really unusable and nonstandard file selection dialogs. One thing I remember being annoyed with is old-style ones that are very small and you can't resize. Here are some, but I've seen weirder ones:

https://i.imgur.com/jYa3qX8.png

With sandboxing, macOS is now forcing devs to use their file selection dialog because it will grant access to the selected files - a custom dialog box has no such blessing.

It's nice, actually; it's finally making the file selection process feel uniform. Too many Java apps are still using random Swing dialogs though...

How do the java apps use their own file selection dialogs if they're sandboxed?

Sandboxed Java apps don’t. Here I’m talking about apps that you can’t get on the App Store, many of which are older Java programs which haven’t been updated to use the newer APIs.

The push to force sandboxed apps to use the system dialog had the nice side effect of forcing many GUI APIs to actually use the native file pickers, which meant that a lot of non-app-store apps started to use the native file picker. But Java apps don’t automatically get that upgrade.