Why are there no good pop-ups in the web [on hold]

Nowadays the UX of web applications has become so similar to classical desktop applications (with SPA) that often I just want to create a web application.

But I always wonder one thing: Why is there no good method for pop-ups? Of course, we can always open up a pop-up, but apart from this really ugly confirmation ("The web page wants so open a pop-up”), the pop-up actually loads a new web page. This makes the entire process really slow and does not integrate well into a SPA.

I really like the pop-up flow of desktop applications because I can still continue working in the main window, just moving the pop-up to the side to still reference something in the application without having it blocking the whole application. Modals are really cumbersome to use and the classical web-popups take too long to load (not as fast as on desktop toolkits).

Did someone decide that modals are good and popups are bad or why is there no movement to implement modern popups (I would think about creating two window objects or something like that)? Or am I the only one who thinks they are extremely nice for “real” work?

(Of course, web sites should not just be able to pop-up a new window, but the confirmation button could just be like the full screen confirmation request).