I could see this being used to create an interesting password storage system. I already use Pass but the one thing I wish it could do is use different keys for different folders, so that I could setup family accounts. This looks to solve that issue, albeit without the Pass ecosystem.
You'd be better off with passage[0] -- it's a fork of pass but uses age for encryption. You can just make a directory hierarchy with appropriate .age-recipients files at the right levels.
I think the gopass pass alternative supports different keys for different folders. I haven't checked it in a while but that was the main reason why I was using it
IMO, it would be easier to use a more feature-complete password manager like Bitwarden.
Then all your non-technical family members can use it like a commercial app while you can Use the CLI or whatever open source tool you want to interact with it.
In my opinion, encryption inside git repositories is an anti-pattern that usually results in headaches.