Not sure I get the equivalence. 😄
But yes, Firefish allows BTC owners to get fiat money without asking them to sell their bitcoins. If you don't need fiat money, you have no need for Firefish.
Discussion
"Firefish allows BTC owners to get fiat money without asking them to sell their bitcoins only if they KYC their coins." would be more accurate. If you KYC your coins you don't need Bitcoin and Bitcoin doesn't need you.