Adobe Illustrator has great tools such as 3D that offers, with a bit of skill on the part of the creative, the possibility of doing good work like the one provided by the designer Coen Pohl. Thanks to your page on Behance we can approach the development of a city with isometric view, which is a good example of what we can do in 3D with this magnificent design tool from Adobe.
The truth is that by using spot colors, which we are used to lately as one of the existing design trends today, we can do great jobs. Below you can even see an animated GIF that shows part of the process of creating a city with an isometric view.
The tool that Pohl uses is "Extrusion and Bevel" which can be found in Illustrator from Effect> 3D. As he himself says, in this design he began to work with the tools and that finally ended with a city that is very well achieved and has a very good finish. It is a laborious process but one that ultimately hides a great result.
As you will see in the animated GIF below, it starts with the basics, which is to assemble all the buildings with their different shapes, and then go into details for what the windows are, to finally give it the color and reduce certain points of light and that with the incorporation of a final filter gives a more professional finish.
You can follow this designer from his own Behance where can you find more illustrations showing the different steps and details in the elaboration of this city with isometric view. If you want to access more information about the Illustrator 3D tool you can access this link from Adobe itself.