just to post something in these weeks, I will show some old photos..
when I started using 3D representations in my D&D games, I started with Paper models..
the disvantage it's obvious..could not reach the same level of realism of resin/plaster models..but for some task could be a nice solution for someone that don't want to spend too much money or don't have too much space.
Take for example this village:
(you can find most of these houses for free, searching "foldup paper models" in the wizard of the coast website or using google)
Imagine to play an encounter in the streets of this village..in my opinon the feeling to be in this village it's transmitted quite well..
All the village could be made with less than 10€ and in the right picture above, you can see the space needed to storage all the houses (!)
Other example of papers models (from Fat Dragon.. that in my opinion with WorldWorks and Dave Graffam Models, it's one of the best paper models company), mixed with a plastic castle:
For dungeons or caverns, I never used 3D paper models.. I realized that for me, they are too much time consuming, compared to the result..If I have to spend weeks to make paper walls, I prefer to spend the same time making and painting resin or plaster walls.
Instead I used 2D or 2.5D paper models (2.5 means 2D with some 3D element like doors, arch, etc but not walls).
I find that for me, Cooper Dragon settings from Fat Dragon games was a good choice..
One of the good things of paper models/maps.. it's that you can find really a lot of different enviroments, or you can make them with program like Dundjinni.
most of the map above are from 0one games..really beatiful maps..and even now that I play with resin terrain, if during a game, I need to improvise an encounter in a certain place, I can search in my "library" of place, if I have it. If the place it's particular (like a theatre for example), and you have just few minutes..sometimes it's better a nice 2D map than lose time to prepair an improvised 3D solution with Dwarven Forge or similar.