For the first six years of FGO, there was no pity system. Players famously spent $1,000+ on a single banner and walked away with only Craft Essences. Private servers emerged as a form of "protest gaming"—a way to use the character you wanted without selling a kidney.
A deep dive into versus mobile emulation. fgo private server
The of anime mobile game emulators and notable copyright takedowns. For the first six years of FGO, there was no pity system
How they work (high level)
Tools like Charles Proxy or MitM (Man-in-the-Middle) daemons. These intercept the official app's traffic on your local Wi-Fi network and reroute it to the private server without altering the app itself. fgo private server