That used to be true in my country too. For some bureaucratic issues, fax was legal-binding. For example, for public health/social pharmaceutical deliveries, it acted as a valid receipt, it was "official". I noted fax used to improve delivery times, reducing errors.

Also there was that psychological effect of paper.

On the Health&Edu sector, most of the secretaries were young girls and they loved to be written something after the official receipt was delivered (the first page in the call). I would write them something as a personal sidenote, and they will do the office work like a charm. Low-rank bureaucrats love to be addressed. These "Social skills" were not used on the official first page of course, but it worked! It saved me lots of headache and phone-drama.

I believe they were, I had a couple of friends who had owned similar ones.

But I'm in my late 20s, so when I was a kid these were already being replaced by better tech