Sites like eBay would require user identity verification whether or not the government required it. Can you imagine the scale of fraud on eBay if users were allowed to set up anonymous accounts and accept irreversible currency transactions to anonymous sellers? It would be a scammer’s dream come true.

I wouldn’t have any interest in using such marketplaces.

As for Brave: Whether or not KYC or other regulations explain their behavior, any cryptocurrency rewards program has an inherent incentive to make it as difficult as possible to cash out. People who cash out almost always sell their coins, putting downward pressure on the price. If they can use dark patterns to reduce the number of people selling coins, the coin price stays higher.

The ideal cryptocurrency rewards program (for the crypto, not the users) would give people coins but almost force them to hold those coins and make it as difficult as possible to sell. This simultaneously hypes the coin by spreading awareness and removes downward price pressure by making it difficult to sell. This almost always means the company or founders have a lot of the coin that they plan to sell off as it becomes popular.

Virtually everything that comes attached with arbitrary crypto tokens or rewards is a scam to make the founders wealthy while the users chase pennies.