That's not really what irreversible transactions means in this context.

What ledger has recorded this transaction? How might a dispute be resolved? What's stopping the receiver from just claiming you never dropped off the cash when you drive back home?

Ah, but if you send money to a bitcoin address the recipient could simply claim the address you sent the bitcoin to wasn't theirs.

And if they can sign a non-repudiable statement that a given address is theirs, they can just as easily sign a non-repudiable receipt when you hand over the cash.

A transaction involves exchanging something (usually a currency) for something else. What you say is that with bitcoin you have proof and irreversibility of payment but the transaction can still go wrong because payment is only one end of the deal. And when the transaction goes wrong you probably wouldn't want a form of payment that is irreversible.

I am not making a claim of whether or not you want irreversible transactions or that they are somehow inherently better than reversible ones.

I am simply pointing out that USD != bitcoin, so the Tesla-driving-cash example is a fundamentally different thing than a bitcoin transaction.

It's like saying "Jeez, it took THAT MUCH energy to get to the Moon? I can drive around the earth a thousand times with that much energy!"

Yes. You can do that. It might be smarter and better for you to do that. But you won't be on the Moon at the end, and there's no way for you to get there unless you take a spaceship.

In this example cars = money, and spaceships = bitcoin.

Often a simple bill of sale is sufficient

"Often" isn't a guarantee.

Turning "often" into "always" is the reason bitcoin exists, and the reason it uses so much energy.

Imagine that you accepted the Bitcoin transfer to sell somebody’s car for them to a known interested buyer, acting as a quick middleman, but then refused or failed to arrange the sale. There is still room to argue about what exactly the “trade” was and whether it was theft. The Bitcoin doesnt simplify resolving it. There were companies filling offices with people to do this exact “scam” years ago in Canada and I never heard of anyone getting punished because there were no contracts or bills of sale to refer to. Having a record of payment (via credit card) didn’t help anyone

The kinds of people who are moving a billion dollars cash and don't want any record it through the traditional financial system have another solution if someone fucks with the deal -- they kill them.

Everyone else will do whatever kind of wire transfer you do for moving a billion dollars.