Not really.

With most cryptos, there is really a strict pre-established monetary policy baked into the algorithm with really no flexibility at all.

"A better question would be not if we need central banks but rather should the economic system be based on credit and interest or not."

I think a better way to say it: "Do we need monetary policy or not" - and I think the answer is 'yes' - so whether it's crypto or not ... there will have to be some kind of group/committee making those rules, and that's de-facto the central bank.