This used to be a lot easier, Youtube had an export function to OPML and you could just import it.
Its quite useful being able to follow all your Youtube channels with your RSS reader if you want to pick which you want to watch then also Metube and the browser plug-in makes it a right click and select to send it for download.
Oh, my… I followed a few subs on reddit. On lemmy I’ve only found https://lemmy.ml/c/degoogle but that’s also the biggest de-x movement afaik.