[lesostep]

Or you can start with minivan buses, and switch to traditional one when minivans stopped being enough In my city less common routes are still purely minivan because why not. Some seasonal routes (more relevant in summer|winter) are also partially or full minivan.

(sidenote: I'm pretty sure it started because few guys with minivans noticed that some areas were under-connected by buses and just started a business driving those routes back-and-forth on a schedule. Then some regulations were slapped on top. So it looks like public transport have tendency to spontaneously appear in denser areas)

[bombcar]

These used to be called jitney cabs or https://en.wikipedia.org/wiki/Share_taxi#Jitney (basically, cabs that travel like busses) and are still common in many parts of the world.

In Mexico it was always a decision of "do I walk a bit further to get the jitney and pay a bit more, but likely go faster (it stops picking up passengers when full and just goes until the first drop-off), or do I get on a bus sooner for cheaper but likely slower?"