Google is required to send you a CSV of your YouTube subscriptions upon request.

If you have an Android phone, once you have said CSV file, you can upload it into the Newpipe Application and voila, watch YouTube without visiting YouTube (or supporting the creators, but that's an aside to this topic). Sadly I know of no way of doing something similar on iPhone.

On desktop/tablet, you can always use Invidious. This is especially useful when combined with the tool yt-dlp and sponsorblock. If you use an RSS reader, you can "subscribe" to YouTube channels that way, and use redirection extensions to redirect you from YouTube to invidious, after that you can use yt-dlp with a sponsor block flag to download the video directly to your desktop, and watch it in whatever quality you want, with subtitles if you want, and have all mentions of sponsors cut out, and of course, no ads.

Obviously, this is too much work for most, but this is what I do to not visit YouTube while still watching their content, which is simply more plentiful and, IMHO, higher quality than what you find on other platforms (save for possibly Nebula).

Rumble is just a bunch of Nazis from what I've seen, so fuck them and their shitty platform.