. A miners doesn't necessarily have to be a cryptocurrency gray hair even a newbie can become a miner.
Threre no such thing as rank disparity in mining,its simply based on computing power,if we're to go back to 2009,then anyone could attempt mining from his/her laptop,but with the gradual development of the system,so also it became more difficult to mine, huge electricity,mammoth capital, mining rig and so on and so forth that costs a fortune
To become a cryptocurrency miner you would need to put together a mathematical puzzle using soft ware for example in bitcoin the puzzle made by satoshi Nakamoto where you get bitcoin after solving the puzzle.
Bitcoin is obviously digital,and isn't physical in anyway,what miners do is,when an order is placed by a customer,its the duty of miners to confirm this transaction and move it over to another block, and they do this but solving a cryptographic puzzle,and the first miner to solve this puzzle is rewarded with
bitcoin from thin air/transaction fees
The 21mln bitcoin has already been programmed,so when a miner successfully confirms a transaction,he/she gets rewarded(they do not technically create bitcoins)