About 20 years ago I worked on a project designing pop-up shelter buildings, and that's a misrepresentation of UNHCR policy.
Their policy is both simple and logical once you know it: The main challenge with refugee camps is not an engineering issue; the challenge is getting nearby countries to agree to host camps. Countries will agree much more easily to host a temporary camp - which means it has to visibly be a temporary camp.
It turns out, once you know about this constraint (and the obvious facts about cost, logistics, and that camps have large amounts of manual labour available) it's extremely difficult to improve on 10,000 year old canvas tent technology.
Their policy is both simple and logical once you know it: The main challenge with refugee camps is not an engineering issue; the challenge is getting nearby countries to agree to host camps. Countries will agree much more easily to host a temporary camp - which means it has to visibly be a temporary camp.
It turns out, once you know about this constraint (and the obvious facts about cost, logistics, and that camps have large amounts of manual labour available) it's extremely difficult to improve on 10,000 year old canvas tent technology.