FTP was always broken, but its brokenness was mostly hidden until the 90s. I can't defend its design or many of the decisions made then. But current, existing, not-broken file transfer protocols exist that can transfer metadata intact, including the most popular network protocol in the world. Every filesystem on every system of any relevance can maintain metadata on the filesystem. People still insist that filename extensions are better than actual, real metadata. Those people are broken. Blaming the 'file' command doesn't help, it's also horrible. Blaming ancient unix programmers is a diversion, most other systems of the time were no better. The Mac is an outlier, unfortunately nobody followed that example.
The filename extension discussion doesn't even touch on other metadata that could be maintained with a decent solution, eg. all the stuff that gets jammed in EXIF headers in JPEG, or other headers in other file formats, all different.