This is definitely something that AS revenue management has picked up on. The demand for regional jets in a 2x2 config in Y is much higher in a pandemic than a 3x3 737. Traveling as a pair is much more common than traveling as a threesome, and the smaller plane means fewer people, which (in theory) means lower chance of exposure to illness. Even the Q400 was seeing a premium over mainline on routes like SEA-GEG or SEA-PDX.

Even pre-pandemic, I always preferred the E175 and Q400 for this very reason since I typically travel with my wife. As strange as it sounds, 80% of the reason we'd want domestic F is just to avoid having a third passenger in our row. I'd take 29 inch pitch in 2x2 before I'd take 32 inch in 3x3, although I have abnormally short legs for a 5'8" person.