Attestation is a service, like every other service. Why should it necessarily be free? Especially now that we all know that "free" on the web means ads & tracking?

I think we should just accept that some things should cost a bit of money and move the discussion to "how much should it cost", rather than trying to sweep economics under the rug.

I think you miss my point: When bots can "give" more money/computing power, then the transaction is no longer a good test of being human.