Prior to the birth of the regional jet in the mid 1990s, commuter airlines fed their major airline counterparts in the hubs. The idea being incremental passengers added from Altoona, and Hagerstown, and Jamestown, etc… could top off a 737 from Pittsburgh to Raleigh. Those airlines - Chautauqua, Commutair, Mesaba, Express One, the Mesa family of carriers, CCAir, Colgan, etc… flew a variety of turboprops ranging from 19 to about 37 seats. Jetstream, Metro, B1900, Saab, Dash 8, Shorts 360. You get the idea.

Mainline flying started at around 65-85 passengers (Bac 1-11 / Fokker 28) with the DC9-30 coming in above that at around 100-110 and the 737-200 not much above that.

The introduction of the CRJ at Comair, and the subsequent and inexplicable sale of scope by ALPA carriers created a permanent industry wide B-scale that has lasted nearly three decades, and creeped ever larger. After 9/11, scope was loosened yet again, allowing RJs to capture more and more narrow body flying while mainline furloughees were sidelined and then sidelined again by age 65. The lost decade that we created.

Now nearly 100 passenger jetliners with transcontinental capability are ubiquitous.

So back to your question. Will the regional model fail? Maybe it will. But if we look at it as a B scale, as opposed to a stand alone industry, would it’s failure really be such a big deal? Airlines will find ways to continue to serve those markets that they can serve profitably. Even if that means bringing that flying back in house with airplanes similar to the A220, 717, and E190. And maybe the next airplanes to serve Altoona and Hagerstown are the new breed of electric 19 seaters currently under development.

As for the regionals, maybe a quote by Kylo Ren is appropriate. “Let the past die. Kill it if you have to.”