Copy trading is the real dividing line
On a centralised venue, the set of copyable traders is the set that signed up. Their track record is whatever the platform displays, over the window the platform chose, for the account the platform can see. You cannot audit it independently.
On Hyperliquid every account's history is onchain, so the candidate pool is every trader on the venue and the record is reconstructable from raw fills. Selection becomes a measurement problem rather than a marketplace-browsing problem.