The question is not about how many people use Gmail - and that still doesn’t take into account corporate users. It’s about how many people use the web interface as opposed to using a mobile app.
To say that Gmail had much to do with Google’s growth considering that there was only a relatively small Window that email was the most popular form of personal (not corporate communication and spam) and that was over ten years ago before mobile started taking over doesn’t really have any basis in today’s reality.
