Bitcoin mining is accomplished with very fast computers solving complex equations, not with picks and shovels. It’s how bitcoins are created. Without bitcoin miners, no transactions could be processed, and no confirmations could be given to validate your bitcoins were genuine. And of course no new coins could be brought into circulation, because no rewards would be given.
The bitcoin network is only as strong and secure as the people and companies who are supporting it, either by running a bitcoin node or by dedicating computational power to the mining process, which is what miners do.
You have the option of setting up your own “rig” by buying your own hardware (very expensive) or alternatively using a third-party cloud-mining service such as Genesis Mining, which allows you to mine bitcoin without the hassles of maintaining your own hardware.