How to make isometric?

Question

Game development

I read various articles about isometry, but I did not understand how to do it on unity.
The question is how to draw this very grid, by what methods? Let's say I draw it with drawLine'mi, but how to interact with it? How to make other objects see it? Will everything be relative to global coordinates, and not on a drawn grid?
Many people say it's better to use 3d, but we want to make games on mobile platforms, and they are quite limited in resources (although it's worth learning more about this).
Articles:
Unity3D Isometric Plugin
Reverse Engineering Caesar III (Part 2, Drawing ...

Answer 1

I don't know about Unity3D, but in theory, it's the same 2D, the same sprites, etc. :) just the coordinate system is "rotated"