Top down view
The micro transit sector has the ability to address a wider audience than public transportation. By combining the “Demand Response” aspect of current rideshare platform with the ability to transport a higher number of individuals using efficient routes that minimize inconvenience, this industry can provide a high level of utility and savings to customers and the public. Utility comes in the form of saved time induced by route randomness (when an uber pool suddenly matches you with another ride share customer going in a totally different direction, in order to capture demand), and by lowering congestion, since buses are more efficient at moving humans than private cars. Furthermore, by transporting a higher number of individuals, microtransit systems can charge less than conventional rideshare, and achieve scale along the lines of conventional public transport systems.
Numbers
Chariot vans hold 14 people vs buses that hold 80 people
~6 chariot vans = 1 bus at maximum utilization
$2.50 each way; at full cost, they're anywhere from $3.80 at off-peak times to $5 per trip. (roughly the cost of a bus ticket)
Arguments against
For-profit microtransit detracts from existing public transportation systems
High cost of operations in the form of regulations (on drivers, vehicles)
Arguments for
Potentially cheaper, robust routes
Where we are
A number of microtransit pilots have started and failed in the past couple of years. Bridj received a subsidy of ~$1000/ride, for 1500 rides and failed. Why? Bad PR? Poor market choice?
Conclusion
Essentially, these services either operate on low ridership routes, that traditional buses struggle with, or high ridership routes that buses would better address anyway.
Arguments that AVs may reduce the cost of operation and increase route capability (as a result of redistributing cost) have yet to be tested
Future
There are situations microtransit makes more sense. Low volume fixed route (nursing homes, hotel transport), hybrid fixed route (demand response rides, planned <~1hr?)