Some fork of youtube-dl would probably do. Personally I use JDownloader 2 (open source) to download not just from youtube but from any other sites as well. It runs locally.

Most of my friends moved to telegram at some point, but attempts to have them move to signal, let alone matrix are futile.

Great thread, although I tbh don’t even want alternatives for most of them.

Lemmy, sure.

Discord, would be nice but until I get my friends and servers to move to something else, not gonna work.

Facebook, I don’t ever want to use anything like it even if it was open source.

Mastodon, I don’t want to use it despite being fedoverse cause it tries to be like Twitter and I hate Twitter.

Pixelfed, I don’t really want to use anything like instagram and even if I did, not relevant until people I want to follow use it since I wouldn’t post myself.

Tictoc, I would rather scoop of my eyeballs with rusty spoon than use it, no matter if it would be federalized.

Others not mentioned I don’t care enough to know how they work. Still, I support the sentiment of making fedoverse alternatives for things, although I personally only need lemmy and discord to get my dopamine fix.