If in doubt, drive.

But it's situational.

Example, SOCAL to PHX or LAS in entirely driveable, but it's long 4-6 hours. There are numerous flights, all day, early, and late and multiple airlines. So flying would make the most sense, with a possible drive if there were wx or flow issues or it was a big holiday travel day.

If you're looking at two legs, then a drive of 4+ hours would likely be worth it, but you'd have to bid stuff with easy first and last days so as not to crash an airplane or car due to fatigue.