Ya don’t need a locking gas cap. Most vehicles made in the past decade or so, have coiled springs in the filler hole. You can’t get a hose down it.
They’ll just take your vehicle or wallet at gun point. If prices continue to climb, you can bet it’s going to get very ugly.
Not to worry - just crawl under the car, punch a hole in the tank with a sharpened screwdriver and drain the gas into a container. That was the standard bypass of the locked gas cap in the '70s. It will no doubt show up again, if it hasn't already.
A guy at work last week told me that someone had punched holes in the dual tanks of a neighbor’s older F-150 and made off with almost 40 gallons of gas.