No, your laptop also connects to the hotspot. If you have available wifi at your location, you can then setup the pi to use that wifi and disconnect the phone hotspot, and just use the local wifi on all devices.
Ive just found this to be the simplest setup. I briefly had serial over bluetooth set up, and it was an easier way to change the pi’s wifi, but it broke pretty quickly for me not sure why.
Probably the most elegant solution is ethernet over usb, but thats a bit of a pain to set up.
For me a hotspot has been the least headache
So the difference here is you are manually doing a thing for your backups. Using a self hosted server and something like immich will seamlessly do it for you. If you drop your phone in the toilet and it breaks, the photos you took since your last manual backup would be saved.
Immich isnt meant to be a photo gallery viewer primarily, it is meant to be a self hosted photo backup service to replace stuff like icloud or google photos. So yeah, dont recommend it as a gallery viewer, recommend it as a selfhosted image backuo service.
I self host a jellyfin service on my nas, and keep all my movies and shows on that nas. I wouldnt be able to fit all that stuff on my phone.
I worked in an office that was paying out the ass for google drive. Setting up a self hosted nextcloud was a great solution and saved them a bunch of money, and still worked as a hands off “cloud solution”
If you dont want to run a separate machine to self host some services thats fine, you dont need to do it. its not for everyone. But plenty of people have reasonable motives for doing it.