That's not it. Other countries with universal healthcare also use faxes. It's a conservative industry and you have less legal risk to send a fax and get another

That's not it. Other countries with universal healthcare also use faxes. It's a conservative industry and you have less legal risk to send a fax and get another signed fax back than to rely on email, docusign, documentsignr.com or whatever. They won't be replaced until it's both very clear and also required to move to some standard digital signature system. This is resisted by the public everywhere because this pretty much means requiring an e-id system.