Airways won't be needed in the future. Using GPS and computers IFR flights can fly great circle routes now. Airways are related to VOR navigation technology which is becoming obsolete.
The reason microjets will not be commercially viable is because of the Democrat / Lawyer symbiotic relationship. The Democrats feed off of the profits of product liability awards.
Cessna is one of the very few surviving airplane manufacturers. They were sued by a wet-behind-the-ears 172 pilot who stalled his plane when his seat slid backwards during a botched landing. No one died in the accident. Result: a jury awarded the plaintiffs $480 million dollars.
The legal leeches make many technologies impossible to implement.