Serial lines are still used on farm equipment!
Discussion
When you need reliability and durability and a USB-C cable just won’t get the job done.
It's been many years, but about 15-20 years ago, I had a local business that used to come into my business and order these custom made cables from us. They were serial on one end and some priority ancient thing on the other. We would solder them and make them for them. I have no idea what machine they were used for, beyond something with chemical containment.