An aircraft has been described as a series of compromises flying in loose formation.

Any modification to an aircraft will (usually) have some advantages or disadvantages. Do you and your wife normally fly on short weekend trips by yourselves? Then a 2-seater will suit your needs - until you need to take a couple of friends to the mountains, in which case you will need to either rent a bigger plane or (better) go commercial.

There's no magic about a STOL aircraft, it just has modifications to allow it to get airborne at a lower speed. The downsides are that it generally uses more fuel to fly a given distance, and that it's more difficult to maintain.

A lot of bush pilots refused to fly Maules and other STOL aircraft for the second reason - if anything broke, the aircraft would be sitting on the ground for months waiting for a replacement part. Even worse, if it broke while you were at some remote Eskimo/Inuit village you were stranded there until you could get someone to come out and pick you up; then you had to get the replacement part, and fly a mechanic out to fix your airplane, all at considerable cost. Whereas with a good old Cessna or Beaver, you could often jury-rig the thing to get it flying (illegal, but quite safe) and fly it back to a maintenance depot.

If there were no downsides to owning a STOL aircraft, everyone would be making them. I suspect that the added cost and complexity of a STOL aircraft is the bigger factor than the cost of fuel or the speed. After all, once the leading edge slats and oversize flaps are retracted, the wing probably looks like much any other wing.