>Plus - how are they going to detect your remnawave node sitting on 443 port? For them it's just some traffict.

What about all the outgoing traffic? That's going to be hard to mask unless you have another VPN for outbound

But what's wrong with my VPN talking to, say, youtube (blocked in Russia) or some torrent site (for example to fetch RSS feed of new releases).

Fedora, for example, provides torrent access (including RSS feed) for its releases: https://fedoraproject.org/torrents/45/