Transactions are not finalized for 30-60 days at banks and even longer for payment cards. This is why you can charge-back. 'Time to usable funds' and finality are not the same thing. And no, Eth2 reaches finality in 12 seconds.
For example, let’s say you sell a car, the buyer sends you 150 ETH, you wait for 3 confirms and he drives away with the car. Then at some point the tx is removed from the blockchain. Now the buyer has your car and the 150 ETH as well. Why did it happen? Because you didn’t wait for tx network finality before giving away the car to the buyer. The amount of time that you should wait is around 15 minutes. Therefore Ethereum is a bad choice to buy coffee with :)
The Ethereum network has never deviated by more than 2 confirmations (24 seconds) and with PoS this is even less likely to happen.
Finally, the likelihood of that happening AND a car buyer colluding with block producers to scam you is effectively zero.
You're FAR more likely to be struck by lightning in the 15 seconds it takes the driver to leave than you are to have their transaction reversed on the Eth2 blockchain.
