Once you get beyond an 8 hour bus ride I suspect most teams are flying now anyway (I have no idea if this is true…just a guess. I use that as my own cut off when it’s more than just me in the car)
And I get it costs more and can be more stressful to go coast to coast, but time wise it’s not that much worse than a 10 hour trip even with getting to and from the actual plane.
I do agree on the lost rivalries and the obstacles it presents most fans of teams who might otherwise go to away games if drivable.