Thanks for sharing that link. Here's a bookmarklet (as opposed to the Chrome extension) to launch this on whatever site you're on:

   javascript:void(window.open('https://www.whatruns.com/website/'+window.location.hostname));

This doesn't seem to work for all sites, for example my site https://charlieegan3.com doesn't work: https://www.whatruns.com/website/charlieegan3.com

I think the link is just returning cached result that was already identified with the extension.

Why no input on the page itself for something like that?

We started with extension as developers/designers found it especially handy for a quick look-up while working on their projects. Not to worry though - we're working on something for the web as well! ️