I'm talking more about things like you can't use apps that haven't been blessed by Apple without jumping through hoops, you can't easily install some third party OSS without installing XCode clutils, for a while you seemed not to be able to use sudo without booting into recovery mode and flipping some switch. Those kinds of things are 'developer-hostile' in my mind because they just make your life harder as a developer, and to what end?

I haven't upgraded and used Stage Manager yet so I don't have any opinion on it.