So, you're correct, but the previous poster did that thing we so often do where we go too far to make a correct point. In this case, the correct point is that

So, you're correct, but the previous poster did that thing we so often do where we go too far to make a correct point. In this case, the correct point is that the waste of energy is to ensure the security of the blockchain (as you correctly pointed out), and not to process transactions. The marginal cost of processing another transaction is completely negligible compared to the cost of securing the blockchain, and so naive comparisons saying that a single transaction uses as much energy as XXX where XXX is the total energy cost divided by the number of transactions is misguided. You could send a million more transactions and the energy cost wouldn't budge. Of course, the overreach is in the part where they said a single laptop could run all of Bitcoin. Marginal transactions are cheap, but not that cheap, and a single laptop couldn't secure shit. (Again, all as you correctly pointed out. I just wanted to clarify where everyone was coming from for readers who aren't familiar with how Bitcoin works.)