THIS! Let's talk more about this.
The RJs were born around 1996 at Comair as 50 seat airplanes designed for hub feed, hub bypass, and to raid competitor hubs.
At the time there were a few - not many - but a few more than 50 seat commuters. United Feeder Service flew the Jetstream 61 - the ATP (advanced turboprop). Some other airlines flew the Saab 2000, the ATR72, and later the Dash 8 Q400.
The lions share of commuters though were almost exclusively hub feed to support the mainline.
Mainline, incidentally started in the 65-100 seat range with the Bac1-11, Fokker 28, Fokker 100, DC9-10, DC9-30, 737-200, BAe146.
Those were good mainline jobs with mainline pay scales, mainline work rules, and mainline retirement.
Airline management decides that if they play a rhetorical game and call an airplane "regional" they can get ALPA to scope it away where it can be flown by B-scale employees that bid against one another to be the lowest paid employees. (Until very recently)
EVERY SINGLE RJ that is purchased equals a dozen or so fewer MAINLINE jobs. We shouldn't celebrate RJ orders, we should condemn them.
We are our own worst enemies, and have been so for almost 30 years.