Space travel technology too. Both fields have had massive advances in terms of the underlying technology (and safety, which you overlooked) but have "stagnated" in terms of the practicality of shuttling people from one place to another.
However, with space travel, there's a growing consensus that sending people is too impractical and, importantly, needless. We can send robots to do our job for us. Likewise, I think air travel with stagnate because air travel will become almost inconsequential for business purposes and will merely be a leisure activity where time is not of the essence.
I'm sure studies are being done in to it, but I wouldn't be surprised if advances in communications technology and work culture are starting to have strong negative effects on compulsory business travel.
That's kinda the general feeling I get when looking at anything space-oriented. Which is part of the reason I get a bit excited reading up on recent robotics & AI progress.
People need too many supporting structures to be at the forefront of space travel, methinks. Once a tech has been proven, people adopt it pretty quickly; if anything, space travel has been disproven in terms of practicality, until some major change occurs.
However, with space travel, there's a growing consensus that sending people is too impractical and, importantly, needless. We can send robots to do our job for us. Likewise, I think air travel with stagnate because air travel will become almost inconsequential for business purposes and will merely be a leisure activity where time is not of the essence.
I'm sure studies are being done in to it, but I wouldn't be surprised if advances in communications technology and work culture are starting to have strong negative effects on compulsory business travel.