I expect that you'd be able to pay a premium to get a vehicle to yourself (or use a different service that offers that). Otherwise you're at the mercy of their algorithms. Based on pickup and dropoff locations/times, each vehicle would pick 4-6 people from disparate locations and then work out the optimal route and drop schedule. You'd get a cheaper fare (or monthly subscription) in exchange for tolerating the extra pickups and dropoffs.
Fewer stops than a typical bus, more nimble, and more flexibility with locations/routes. I imagine we'll see apps that offer a further discounted fare if you move closer to a thoroughfare for pickup or accept a dropoff short of your house (e.g., end of the street).
That doesn't seem too unreasonable. The car-summoning services like Uber and Lyft already offer discounts for opting into shared rides where other riders may join you.
Fewer stops than a typical bus, more nimble, and more flexibility with locations/routes. I imagine we'll see apps that offer a further discounted fare if you move closer to a thoroughfare for pickup or accept a dropoff short of your house (e.g., end of the street).