But if the price or terms of ownership of something like domain ownership were legally defined using a reference to beneficial owners, that would make ownership the result of fraud (if terms haven't been complied with) and therefore precarious when such owners are discovered later.
The possibility of losing a valuable domain later due to discovery of that breach of terms would create an incentive against that kind of fraud.
If the terms are just to set a higher price, without requiring beneficial owners to be named, potential owners might be willing to simply pay the higher amount without revealing who they actually are, to ensure they don't face the risk of losing the domain on discovery, and that would achieve the original goal of raising the price.