Thoughts on Metis (optimistic rollup)?

Was looking into various scaling solutions for Ethereum and stumbled across Metis which utilizes optimistic rollups as well as being the ability to easily create DACs with built-in traditional business functions like payroll, etc. Maybe u/vbuterin can answer this but I remember him saying ZK-rollups are the future of Ethereum scaling. So, do you think optimistic rollups (specifically Metis) will then become obsolete and replaced by ZK-rollups or do you think both can exist in the future of Ethereum.