> Imagine if when visiting a website you had to remember whether or not it's HTTP, XYYZ, or FKME before typing the URL.

Old farts like me don't have to imagine it. In the mid 90s, gopher and nntp URLs were quite common. It wasn't a big deal.

> Imagine if all email addresses couldn't communicate with each other.

That used to be a massive problem, but Eric Allman solved it before my time.