There was actually a successful airline that did this for decades in Europe. It’s was called “Flybe”.
Turboprops actually cost half as much as jets per seat mile. So they had extremely impressive prices and could operate out of otherwise unprofitable airports.
They went under because it’s operating loans were in dollars but it’s income was in local currency. When the local currencies all dropped compared to the dollar they went bankrupt.
Flybe went under because of leases on fancy Embraer jets which looked good but were uneconomical on their routes, proof of the point really.
Blue Islnds, Logan Air and Eastern Airrlines will probably pick up the routes, and the common factor with all three is the ATR 72 either all or most of the fleet.
Back on the topic of the Cessna Sky Courier many of the small carriers in Tanzania and Kenya were looking at the project as a replacement for the Twin Otter or upgrade from the Caravan when I left last year, cheaper than the DHC 6 and better costs than the Van if you have the loads, I suspect the current virus issues will put that back by a few years for most until travel picks up again.