Since you asked, my answer would be “kinda.” I would be in favor of a domestic air and (non-commuter) train vaccine requirement.
-“But the vaccinated still get and spread COVID.” Far less. And with less collateral damage by way of hospitalization. They will take a bed multiples less often than an unvaccinated traveler.
-“But freedom of movement and commerce.” Shut up and drive. No one said you’re confined to your township, county, or even state.
We restrict international travel consistently, pandemic or not. While disease burden is significant, yes, I think a vaccine requirement for certain modes of travel is a fair compromise between open skies and airline business and a shutdown. Besides, almost 80% of eligible customers have already made themselves travel ready.
And, for Pete’s sake, if you travel right now: follow your destination’s mask and distancing protocols without comparing everything to whatever town you reside. Don’t be “that tourist.”