Why is level cap hard to expand?

I’m a software engineer working with cloud hosting by profession, so I really dont mind training wheels for my home needs. In fact it is preferred because I want to spend the smallest amount of time possible just solving my problem (easily sharing photos between ios and Android without relying icloud or google). I do enough hard stuff at work haha.

14TB is perfect. I could probably get away with a four bay setup with a RAID config for redundancy.

A little off topic, but whats the estimates starting cost to using Synology? Ive been looking for a good syncing solution for media between my partner and I. Any good resources anyone has to share for getting started?