Greasy Fork is available in English.
Adds the option to export subscriptions from YouTube as an OPML file of RSS feeds.
< Обсуждения Export YouTube Subscriptions to RSS OPML
Please submit feedback on GitHub, not here - I don't check these reviews often.
That said - great idea! I've done just this as the sidebar keeps changing lately and the manage subscriptions page loads all at once (no having to expand).
Works only up to 1000 subscriptions. Could you make it to work on https://www.youtube.com/feed/channels so we can get every subscription.