So, the first skyscrapers (or "tall buildings") went up in the mid-to-late 1800s, enabled by improvements in steel, elevators and concrete. They were ~10-12 stories tall at the outset. 100 stories wasn't till the 30s
First, these things need deep foundations. The prospects of what that might dig up in the city DELIGHTS me.
Now, we have the question of where the iron comes from. While I'm sure there are mines, I assume there's a fair amount of re-use.
Early skyscrapers could, effectively, be private kingdoms of wealth. No need to go walk the dirty streets or deal with madness and monsters - just sit in your modern castle, and metastasize into Robber Barons.
Bear in mind that Duskvol has weird metallurgy (steampunk!), and a variety of material limitations and opportunities which can be used to justify almost any kind of special weirdness.
I can't quite come up with an excuse to go full brutalist, but there's still a LOT to do with how concrete gets made, since it's actually complicated and variable.
So, obviously, leviathan blood can go in the mix.