I've read on reddit that Google still provides unlimited photos backup if you own Pixel 5a and lower. On rooted Android you can fake that and get free backup storage, but who wants to give pictures to Google?! I was thinking if it's possible or done by someone to create an environment on Docker by faking device info to access that free storage and backup rclone crypted files as images (by .jpeg fake extension or something)?
I am not sure that can be done. For some devices, the free backups only apply to "Storage saver" quality, which means decreasing resolution and quality, which obviously couldn't be done here.
Secondly, there is some file size limit. I think 50MB/image, but you could split the files, if it worked in the first place.