The first step normally would be as basic as ruling out the key as the problem, but you mentioned something that jumped out at me.

Assuming you have a good key, the steering wheel lock is really the only ‘trick’ I know of when a key won’t turn and you already said the wheel turns freely and isn’t locked. That part kind of seems odd doesn’t it? The steering lock should always engage if you try to turn the wheel with no key… have you had any symptoms before now of a failing column lock? Car turning off, orange steering wheel light on the dash, maybe even an error about the steering column lock on the MFD? There may be codes stored but if you can’t turn the key you can’t run a scan.

I’m no expert and I haven’t worked on non-golfs, but generally the column lock and ignition work together to allow the car to start, so I wonder if the column lock module could be at the root of this. Either it isn’t getting power, it’s not being commanded to turn on / off, or it has physically kicked the bucket.

Or maybe I’m way off base.