It’s new (and buggy) but it’s free. Yes you retain ownership but you understand that it will examined by software for autotagging, etc. I think the point of Raise is for sorting out your imagery by tags, which are analyzed out of your images by their AI engine. You can manually add tags and such, and can apply global tags to upload sets.
I made an account to try it (the iPhone app) out. Looks interesting. I tried browsing to my page on the web but instead of photos I’m getting an red error triangle.