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.
There is, however, a fixed component cost to building such a setup that gets amortized the more disks you buy- I believe it becomes worth it to use a NAS cost-wise over about ~5-6TB of data (and definitively worth it when you get into the tens of terabytes).
Or if you need low-latency storage / any type of performance - neither the cloud nor my homelab has removed my need for my portable NVMe drive