It was initially difficult to understand the motivation because the first half of the post failed to establish "the problem" clearly. I hard to read the entire thing before I had some idea who this was written for and regarding.

The second half clarified most of this but I think the article could do with some revision.

Under any URL-ish scheme, including any simplifications suggested here, nontechnical users will be unlikely to do anything except clicking and copy/pasting. So it really doesn't matter at all to them what the actual text string's structure is. It seems like maybe the article is trying to suggest "advanced" users would benefit from a better system.

Notice that in the screenshots posted, each browser varies somewhat in how it displays the current location. Regardless of the syntax used in a URL-ish string, the browsers can certainly improve the display of this important information.

What about something like this:

https://i.imgur.com/PTs55Tl.png

Where you only show "nonstandard" portions if they are present, and they can be given special coloring to help alert the user.

When the user interacts with that portion of the UI, they can paste in a URL like normal, just when it is displayed, the parsed version can be shown instead to help them see clearly what they are looking at.