Yes, the 737/320/75 are picking up a lot more of the 88 flying which has directly resulted in trip degradation. Yes, the company has been legally squeezing credit out of trips which has resulted in trip quality degradation. This doesn't mean that the trips aren't more fatiguing. They are. It also doesn't mean I don't support bringing RJ flying back in house. Just because we are doesn't mean we have to fly tired. Our trips now are often more tiring than some of the RJ flying I did.
One thing to remember as well, turn times on the larger NB jets are usually 20-40 mins longer than the 88 was. I routinely saw sub 50 min scheduled turns at out stations. Now I see 1:10-1:20 turns. On a 4 leg day, that's an additional hour minimum of FDP.