And that they are the only real competition which keeps us in a situation where we actually have a choice in browsers.
That isn't true. You've got WebKit-based browsers, LadyBird/LibWeb/LibJs, Goanna, and others. Why choose Mozilla to lead the efforts, when another open source community/foundation may be better? You can also participate in the various new web specifications yourself too if you're not happy with the direction they're headed.