Any one used Immich for Photo server / backup?

I currently use a low powered Celeron-based PC that hosts several websites, media servers, FTP servers, IP camera DVR, NAS, etc. Self-hosted cloud is also one of its functions, of which there are much more comprehensive solutions than Immich. Of course, you may be able to use dedicated NAS to achieve this but I prefer a Windows based server due to flexibility in choice of apps and the very low hardware costs.

NextCloud is regarded as the most feature-rich with great support for media files but it is only available for Linux based Operating Systems. You will need to run it in a VM or a Docker container. Installing it is not easy, especially when giving it access to a Windows Folder. If you want to go for a Windows solution, there is Aurora Files, which I have used in the past but I now use Seafile. Unfortunately, the SeaFile code for Windows has now been deprecated and as of now, is exclusively Linux-based, hence I am using the last Windows version, prior to it being discontinued.

If you do give Immich a go, the website clearly explains how it works. You will need to run it on a server, preferably Linux based, but once again, if you are using Windows, it has to run inside a Docker container or a VM.

And one other thing, you will need outside access to your home network, so if you don't use a static-IP based internet provider, you will need to set up a localhost tunnel (eg. PageKite) or use a Dynamic DNS service with port forwarding on your router.

Not quite what you asked, but I use a Pixel (the first version) - It includes unlimited original quality uploads to Google Photos for life.

I just transfer all my photos to my Pixel to upload.

How many GB are we talking here? If you're only using phones to shoot, you'll really need to be hammering them to have heavy storage needs. If cloud storage isn't viable, you might be as well going with just a USB drive plugged in to and shared through a router.