You used to be able to UNLOCK an iPhone with Cydia for free once it was JAILBROKEN...WHAT HAPPENED?

Back in the day I could jailbreak an iPhone than use an app in the Cydia store to unlock it. What changed? Now a days you gotta pay for it or buy a sim. I know there is a difference between factory unlocks and untethered unlocks, but do both still exist.

I can't find instructions anywhere