I use Immich, but saved me money it has not. Unless you actually go through the "Backing up your photos" step, you _will_ lose your photos, it's just a matter of time. And if you're like most people, that is probably not acceptable. And by the time you do the math for the cost of your backups, you'll find Google Photos pricing is actually pretty good. Still worth it, imo.
is nas + backup to amazon glacier a good solution?
I do a bit of a hybrid. Borg to expensive, always available storage, but really large stuff that rarely changes and is less important, I exclude and manually throw in glacier once a year or so. Think, all your blue-ray rips, etc.