No. They would be doing other productive things. But right now, they have to spend their productive power on driving buses.
This is simply a huge waste of human potential.
Car commutes are shorter than transit commutes in well-designed cities.
But even otherwise, you don't need a dedicated full-time driver.
First, you want to solve the problem of long bus intervals. It's still not economic to just buy more buses because they require a lot of power to run and do tons of road damage.
But you can make buses smaller! And by making them smaller, you can run them faster without incurring a lot of useless overhead.
Heck, you can just idle, dare I say _park_, these unused small buses when there is no demand. And since it's so easy to manage the fleet this way, you can make personalized buses for every passenger.
Hmm... It really reminds me of something...