[runeks]

Bitcoin mining on a block secures not just this block's transactions, but the transactions in all previous blocks as well. For each block that is added to the blockchain more transactions are secured by the following blocks. Consequently, these "power usage per transaction"-figures are misleading.

[imtringued]

Although you are correct I feel like you skipped over an important detail that is crucial to your argument.

The power consumption does not depend on the block size.

Securing blocks has a cost that is independent of the block size. Bitcoin Cash is a good example.

I also find it interesting that Bitcoin Cash is not as prone to deflation which means that in theory you could actually use it as money. It never caught on so it is effectively dead though. It's best to forget about it.

[sammax]

Not really. You could interpret it as older transactions are massively more expensive than newer ones and every transaction we make will have perpetual upkeep costs for as long as we keep running Bitcoin, but the overall result isn't changed by that, the average cost per transaction is the same