The inherent problem with creating a new browser/platform is getting people to create addons/extensions for it.
If you don’t think Google could do this, think again. Google has an iron grip on the Chromium project.
From the beginning of its time with Google, Android was touted as THE open-source phone operating system. The Android Open Source Project was used by several projects to create their own version of Android.
Then at a certain point, Google introduced an app called Google Play Services. This app is not open source and contains all of the stuff you need to access Google’s services.
I mentioned Widevine in the article. They came out and said they don’t support open source.
I’m a bit on the fence regarding WideVine. It is important to keep everything open, but broad adoption is also important. Not implementing DRM would make Firefox unusable for many users.