Any number of cities have this "problem" with rather dense uptown/midtowns, devitalizing the downtown areas, and you do your fantasies: uprooting those buildings and transferring them to the downtown areas, which isn't going to happen!
I believe St. Louis has this "problem" as well, given the photo spreads I've seen of St. Louis. Ditto to Detroit and Houston.
Here, in stuck-in-the-60's Las Vegas, they've created a whole new downtown area out in Summerlin, 25+ miles west, called Downtown Summerlin.
And, there's Hughes Corporate Center, a parklike area, close to the Strip, with one tall tower and other smaller towers of 10-9-8 stories. How I wish somehow, those buildings could be relocated downtown! Dream on!
I didn't realize there were steep hills leading down to the riverfront, which invites the possible idea of tram some day, along with some riverfront development or park. Even a simple tram, like they have in downtown L.A. rising up to Bunker Hill!
The main reason Minneapolis (City of Lakes) has developed such a dense downtown area is due to the Lake Calhoun/Kenwood/Lake of the Isles Nimby's around the Uptown district, who have squashed any mid-rise or high-rise plans around their precious lakes. When I lived there, I saw proposal after proposal shot down. In the early 70's, miracles of miracles, with the intervention of Senator Hubert Humphrey, no less, a 21 story tower (Lake Point Tower) got built, and nothing since then! I see they are finally building some apartment buildings around Hennepin/Lake but nothing taller than 4-5-6 stories.