Why do we need 3rd party users (miners) to confirm transactions and update the blockchain for us when anyone who has a valid copy of the blockchain can do it for themselves? By getting rid of 3rd party confirmations, transactions would be nearly instant and there would be no fees.

New coins can instead be generated as a % bonus to payees by an algorithm in the transaction process. Users could then 'mine' new coins by simply moving them between accounts and this appears exploitative at first but is necessary to compensate for deflation and create demand. Perhaps there are mechanisms that can minimize the consequences of abuse and keep it fair.