I suspect O2 sensor life is influenced by driving style.
Here in the city I see drivers who stomp on the accelerator (like it’s a toggle switch) to go stop sign to stop sign at every block.
The whole drivetrain goes through a lot of transients, hard shifting, etc.
I wouldn’t want to buy one of these cars used.
A 4 cylinder and no testing requirement? Keep your money in your wallet for now…