Maybe they should, but focusing on adding new features endlessly is how we ended up with this state of internet browsers. The most complex app running on a desktop are too big, it’s basically impossible to create a new one. (Yes you can fork but that’s just adding toppings to ice cream). The browser war ends only one way.

If we break up the do-everything application into significant parts then a healthy “war” can exist. Why does a browser need to play video, you already have an app for that.