The issue is that as web software becomes more and more complex and desktop-esque, it needs features that were common in desktop software. It's a poor user experience to open a new window for lots of things in the browser, but that sort of functionality is still needed sometimes.

If I think about the engineering product I work on and where they do have modals, none of them would work with a separate page. It's things like "Load one or more of your saved graphs (which you can search and filter) into this existing page of graphs"