Detective Pikachu wants to take a very real approach to the world of Pokemon. For the team creating the movie, that meant staying away from direct-rips of locations and buildings from the Pokemon anime and games. Nigel Phelps, production designer on Detective Pikachu, fully explains the approach in the comment below.
"We've kind of shied away from [using landmarks and architecture from the games]. There are little clues with the street names, and stuff like that, there’s references to the Pokemon universe, without being specific to it. So we’ve shied away from the animation [because] the cartoons and stuff felt much too cartoon-y and unreal, and it was important to everyone making the film that this was a realistic universe."