I think the oil crash, and then the pandemic, really crushed a lot of downtown Edmonton development momentum. Add in unknown reasons to increased homeless and we got an exodus out of downtown. I know all this was not specific to only Edmonton, but the soup just seemed to mix really well here.
I think majority of people in Edmonton just really love their truck accessible wide roads and are generally car-dependent. When I lived downtown Edmonton in the mid 2010s one of my biggest observations was how dead the streets were during the day especially weekday, and I'm talking foot traffic on 104 street. To me that proved that even though we had all these new towers on 103/104, majority people living there always hopped in their car when they left the house.
I would also assume that with Edmonton's downtown workforce not being all that big, a lot of people living downtown don't actually work downtown (or at least a larger ratio than compared to other cities). But then add in all the negative impacts I had mentioned above, and a looooot of people probably said f*ck this I'm moving back out to the burbs where my truck can fit any road and I don't have to deal with bums. Causing a huge price drop in condos because simply, nobody wants to live there.