Is mining necessary for the transaction If someone doesn't want to mine, this means that they don't create coinbase transactions. Coinbase transactions are necessary for every transaction.

Can one spend their bitcoin without having to mine?
Mining is necessary to create bitcoins, which happens with a coinbase transaction.  But they can be transferred from person to person after that without mining.  (Mining is still used to confirm those transactions, to ensure they cannot be reversed later; but the people making the transactions aren't responsible for that part of it.)

Think about the following analogy.  Regular money is created with a printing press.  But you yourself don't need a printing press in order to make transactions; somebody gives you money, and you give it to someone else.  Sure, at some time in the past, someone had to print that money, but that isn't your concern.