There is a program in the Mac App Store called Magnet, could try that. I think there are some others.

Can you use a different extension/plugin?

I think Mac just added window tiling by default now. There were extensions you could install otherwise.

I like how they were like “you can’t fork this repo” and it’s like — actually yes I can.

I like Mozilla, I respect their mission and their good nature. I can’t help but feel the billions they receive from Google make it too easy for them to be, at best, unfocused and, at worst, lazy. They offer a lot of random services like this. I fear this play is just chasing another possible mediocre revenue generator for them. Like pocket, like Mozilla vpn and private relay, etc.