But they are both "Regional Jet"IMHO, you can't compare the CRJ & ERJ cabins. CRJ is much more cramped.
Flown a lot on TUI fly's ERJ190 and pretty happy about it

It's like when some people say that jet aircraft are always better than turboprop aircraft (ATR, Q400). Because for many people (including avgeek) turboprop aircraft means old aircraft or not reliable aircraft (in French vieux coucou). In both cases, many people (including avgeek) underestimate the huge capability of Regional aircraft.
Airlines make also money, because they use the right aircraft on such a market. As always i say it, Airlines order aircraft not only to satisfy passengers or avgeeks, but firstly to meet its needs