Your long post explains in detail many of my same feelings too. While some more recent changes to USF do seem to be at least slight improvements in terms of guest popularity (Dreamworks Land, Villain Con, Fallon, etc) over what was there before, everything post-Diagon has felt cheap. Obvious signs they were cutting corners and not being given a larger budget to do more.
Dreamworks is certainly more popular land, but it's still a sad looking area. Shrek's swamp play area lost the water splash pad and the water guns since opening as well which makes it feel even more empty.
I thought I was the only one who can't help but cringe at the Bourne pre show. The fake walking, wooden acting and obvious green screen reflections kill me. The show is very enjoyable, but T2 had more flashy moments and a more polished looking ($$$) overall package.
The addition I've enjoyed the most to the park is the new Duff Sour beer, ironically

It makes being in Springfield more tolerable since that's in super rough shape right now.
The frustrating part about all this is that is Pokemon had just gone in here, they could have solved so many of the parks major issues in one fell swoop. Additional non-screen attractions, more stuff the kiddos will like, a new land that actually had the proper budget given to it that feels ambitious. I hate that the timing of contracts and/or space constraints had it end up in IOA but here we are. USF really needs another ground up land with some love, care, and proper budget. Springfield can't go soon enough, even if it means I have to say goodbye to that sour.