They are still going on Lightning, not Nostr (we all have LNURLS). Many big channels do routing for free, I understand why exchanges do it, some other routers offer free routing, but charged a one time fee for opening channels. So much of what's going on here is Wallet of Satoshi to Wallet of Satoshi... if they are smart, that's just numbers on a database and not really a real Lightning payment, but idunno. Alot of it is free anyway even a custodial Bluewallet (which they are phasing out) to a Wallet of Satoshi.