Developers, please stop making add-ons and extensions for Google products. You accelerate Google's domination and vendor lock-in when you do.
I could say the exact same things about iOS apps. Or Android. Or Windows. But a bit of competition is generally good.
There are platforms where developers need to stop developing. iOS was the main one; it has extreme lock in, an unfriendly development environment, an extremely unfriendly publishing environment and is actively doing evil things. But no, all aboard the ios apps train!
Windows I could say similar things about but given the competition I really can't. Android... Definitely not. Some of the most free mobile OSes run atop of android.
But when it comes to developing on platforms in general, developers absolutely need to use themselves as a voice to tell other platforms what is good, what is needed, etc. There are excellent general desktop features that people have found on mac os, windows and linux alike. Without developers to make use of them, regardless of the "open" or "closed" state of the platform, users are worse off.