I made a website dedicated to truly free textures some time ago, maybe some people here have a use for that:
https://duion.com/art/mainClick on the categories on the left for the pictures.
All textures are licensed under Creative Commons Zero license which is basically public domain, which does not even require attribution, so they are completely free to use.
When I started doing 3D modeling and level design I had really trouble finding textures that are truly free to use. Since I'm doing a free open source game I can only use compatible licenses, which excludes almost all known texture resources on the internet. Almost all websites have some kind of annoying registrations, logins, paywalls, download limits etc and even if you made it through all those things, you were still not allowed to redistribute them, since often you would end up with some kind of royalty free license you are not allowed to redistribute like you do in an open source project.
So I decided to change that and started making my own textures including a website where I share them. I know times have changed quite a bit recently in 3D modeling with physically based rendering and material generation software, but I prefer using photos, as textures like seamless textures for achitecture, or for stencil painting 3D models or just as reference.