It was the type of product that was an engineering impossibility to launch at the time. Mobile browsers of the time (and many users' desktop browsers!) couldn't run JS quickly enough to allow for the real-time experience - and reportedly Wave would consume 300-500 MB of RAM at the time, which was a ton for 2009!

https://theappslab.com/2009/10/05/google-wave-the-aftermath/

So they would have needed to invest in native mobile apps, and in significant levels of optimization. And none of this, not web or mobile, had the developer experience necessary to iterate quickly enough as the UI would inevitably evolve upon contact with customers, and you'd end up having many widgets reflecting a centralized global state.

Not to mention that you needed sticky server-side sessions to run the operational transformations efficiently, which harkens to the KV caching challenges that still challenge us today.

But it was an incredible dream, and it was a key source of inspiration to me to choose CS as a path.