Is it really expensive...? I currently pay for the $3/mo 200 GB plan and share it with my partner. 18 years of photos takes up about 100 GB and the rest of it is shared across Drive, Gmail, device backups, etc.
It's only $10/mo for 2 TB of storage, or less if you pay annually. Sure, that's a bit more expensive than buying cheap cloud storage, but you know how much I've had to support my non-techie GF over the years? Pretty much zero. That peace of mind and "just works" is easily worth the few dollars.
Now, if you have many many terabytes of files, that's a different story... maybe put YOUR stuff in cold storage (in the cloud I mean) and just keep the shared photos and such in Photos?
