I just assume that anything owned by a tech corporation is actively spying on me with anything they got. And I think it is reasonable to assume so, specially when they have weird stuff in the EULA(as I believe discord has). So yeah twitter reddit discord, android, windows what have you, are probably gathering as much data as they can and selling it for as much as they can get.

I found a YouTube link in your post. Here are links to the same video on alternative frontends that protect your privacy:

• yewtu.be
• inv.nadeko.net
• yt.artemislena.eu
• piped.video