That would be more efficient, but there are enough places with no bus or tram. And then you have services that are infrequent or shut down early and could use some help.
Which btw that program isn't doing too well. It's a huge cost right now, compared to more traditional public transit. And imagine that this is with regular "cheap" vans rather than more expensive vehicles. These also seem to be a small step better than Personal vehicles as I hear most rides are solo rides (which is not exactly the aim). What is great about micro is they support bikes, and people with disabilities to help reach the last mile in their trip.
I’ve never had a solo ride in one, and I never noticed anything about their vans that seemed cheap. My biggest complaint is that you have to order one hours in advance because they’re so busy. That might depend on the service area you’re in though.
AFAIK all the buses here support bikes too, at least all the ones I’ve been on with Metro.