Blockchain will not exist correcty withour miners(or 'transaction processors'). Although It seems to be possible. Instread of proof of work there is a chance of using Proof of Stake as an alternative. In that case, we don't need 'miners' to solve a cryptographic tasks. The main tasks for Miners is to check if all is good with Blockchain. I know that we have "audiotors" as well but Miners are mainly important because their purpose is to: provide a decentralized mechanism for determining which version of history to accept