I end up using yt-dlp on macOS/Linux to download videos if needed. It’s worked on pretty much everything I’ve tried it on so far. Though admittedly not at seamless as a button being injected into the page itself.
Does youtube-dl still work? There seems to be a cat and mouse game with these things. I won't update it for a while and it will break, but it always works again after I update. I figured without active maintenance youtube-dl would be pretty useless by now.