You mean far, far easier to intercept? You used to be able to just stick a coil around the wires.
The main issue is just a lot of countries governments’ don’t trust computers still. In Germany they insist on fax and post as it’s the only thing they can use as proof of signature in court, etc.
But it’s government laws and regulation that is behind. It’s not so much of a technical problem (although E2EE email standard would be nice!).