The intent was there would be other operators and ways of specifying some sort of resolving agent. It was a pretty interesting idea but Microsoft destroyed internet technology competition for the next 10 years and the rest was lost as the next time someone picked up basic web technology it was a search engine.
On the semantic web thing, in the end, it turned out URLs are useful for everyone — at the very least because a URL is something you can share with other people and be sure they'd reliably end up seeing the exact resource you want to direct them to. Same can not be said about anything that involves web searching. Search results move around all the time for a million different reasons.
it's a victim of "all the ways for all the people", and it can't do either very well.
The optimal middle ground for me was the separation between search query bar and URL bar.
And why did we combine the two? Well, it was to reduce screen clutter and combine features so that we could make room for....
making the URL bar longer, generally far longer than any sensibly human-readable URL. Brilliant!
(the REAL reason was because Chrome wanted to shovel people into Google Search as promptly as possible, and that started a Stupid Browser Trend that firefox got suckered into following.)