The frequency argument seems reasonable as driving yourself to the same location is generally worse for the environment. What makes flying bad is the rate you can travel. You can fly 2 million miles far easier than driving an IC car that distance.
Of course this assumes commercial aviation, private jets are much worse for the environment.
driving yourself to the same location is generally worse for the environment
Curious what this is based on, taking road construction, car ownership, etc into the calculation? Because as for fuel consumption clearly it depends - if you're a family, taking 1 car is generally going to be more fuel efficient.
I was just assuming a single passenger thus ‘yourself’ and normal distance vs fuel. For a couple it’s likely still true as the break even point for fuel would be around 40+MPG. That’s assuming you’re not increasing congestion and thus lowering others fuel economy and flying does not make this trip much shorter or longer.
A family is as you suggest likely better off driving unless they are renting an RV. But, IMO avoiding a 10-20+ hour road trip with a car full of kids is an excusable reason to be less fuel efficient.
PS: At scale things tip further to flying as roads have a separate set of issues.
Of course this assumes commercial aviation, private jets are much worse for the environment.