I think you misunderstand what the Bitcoin network actually is.  It is a globally distributed account book keeping track of what balance each account number has.  Transactions are just requests to move a balance from one account to another.  "Mining" is just securing a set of transactions (a block) with cryptography so it is easy to prove the transaction history has not been tampered with.  Keeping the account books is a useful function.  Every bank and stock brokerage has to do it, so they know which accounts have what balance.  The Bitcoin network rewards people who do this useful function with a fresh balance that didn't come from another account.

But keeping the account books is not the only way to earn income, and in fact because it is so easy (it's automated, and requires no work on your part once you launch the software) it is very competitive.  In the long run you are better off doing something else which is not so easy, and therefore does not have every Tom, Dick, and Harry using their gaming rig GPU to do it.  Yes, doing something hard is actual work that takes actual effort, that is what "earning income" is.  Turning on mining software is about as hard as turning on a water faucet.  It's not actually work for you, and you can't expect to make free money doing it.