I meant on-chain vs lightning - like if bitcoin is world reserve currency then would most people only ever use lightning and on-chain is stuff for creating / settling channels and really big payments, because on-chain trans. per sec is limited?

Let’s throw some numbers around. Let’s say we hit 1 million transactions per second. That’s 600 million transactions per 10 minutes. If a block holds 6k transactions, then only 0.000166% transactions can be on-chain per block. How high might fees get at this point, in BTC, is what I’m wondering.