the gas station does that because it has no way of knowing in advance, when it authorizes your purchase, how much gas you are going to pump into your car
so it actually makes sense
they then only actually bill your credit card for the amount you do in fact pump.
if you don’t want that hold to show on your account, you can go inside and have the attendant charge your card for a specified amount in advance (or most gas stations will agree to hold your card inside while you go and fill you tank, then you go back in and sign and pick up your card).
so you do have a way around this problem.
What really makes sense is for them to charge the actual amount of purchase. They clear what they want in advance and adjust the amount when the purchase is complete. In fact link the pump to the purchase amount charged on the card.