Most of Gattaca is shot indoors and the sets have a very minimalist aesthetic. It looks futuristic, but since their budget was quite low* it was also a way to keep costs down. The visuals bear no comparison at all to Blade Runner. It's an incredible movie nevertheless.

* I quite enjoyed how astronauts wear a suit and tie even on spaceship launches. Out-of-universe that was probably because they didn't have the budget for spacesuit costumes. But in-universe it is still legitimately a "space suit" and might be a nod to how formal the Gattacca workplace setting is (I've read too much r/moviedetails).