I'd argue that you're not really hurting the torrent, since most torrents are already pre-cached. It only needs to be cached once for thousands to enjoy the file.
Yeah it's not ideal, but one hit and run isn't going to make a dent in the grand scheme of things.
Stremio isn't going away, just like Qbittorrent isn't going away.
It doesn't actually host any illegal content. Stremio alone is nothing more than a film and TV database. It's not illegal to make a database.