I was thinking of web apps like MS Teams that just simply do not allow to open a new tab on click for whatever reason. I can open the app in two windows just fine, but I can't right/middle click on something to tell it to open in new tab. Why would I not want be able to open a Word Online document in a new tab directly?

There are other apps, that are even worse. Allowing something to open in a new tab/window but identifying that there are multiple windows open and just disabling all but the main window...

I don't understand developers that do this. I always felt that multiple tabs is a strength of the web. They worsen it somehow.