That thief must have been dumb as a bag of bricks, which is not a surprise. You can't really steal an iPhone other than for parts because you won't be cracking iCloud lock.
What's really funny is how trivial FRP is to bypass on Android, whereas a stolen iPhone would be useless other than for parts, and even then they're all serialized anyway
Factory reset protection. It'll ask the last Google account logged into a device before you can set it up if it's not reset from the OS (recovery).
It's a Google service that does this, so it's kinda stuck on top of android, no matter which phone it is, including pixels. It's been super trivial to disable this service for long enough to get past setup, where you can then sign in with any Google account and the device will function as normal.
iCloud locks however prevent the phone from going past the setup screen if you don't have the previous login. This is baked deep into the OS, and while it can be removed with a jailbreak, it's near impossible to jailbreak it before getting past setup.