I agree with your observations, but your comment gives the perfect context to understand why in my opinion, by rapidly expanding web standards, Google makes it harder for independent browsers to sustain themselves (deliberately or not - I don't know).

Web API surface is large, and if we see new features like: https://news.ycombinator.com/item?id=43113790 and developers start using it, then websites start to "look worse" in Firefox (or work slower if polyfills are used).. then in order to keep up, Mozilla might feel pressured to expand their engineering team to implement things, and this is expensive..