So I did so me digging for 'royalty free' and well, yes kinda. And mostly no.
But I reckon wikiloops is a the best I've found so far. https://www.wikiloops.com/knowledge/use_of_tracks_outside_wikiloops.php
The ones that don't expressly mention it or non commercial use is kinda vague
https://www.guitartonemaster.com/
https://www.guitarmaps.com/Free-Guitar-Backing-Tracks.html
I did spy a few royalty free playlists on Spotify and channels on YT. And did go through a few where a once off payment ($15-150) get you lifetime royalty free access to their library and lots of subscription based ones.
You guys find any?