Google wave was largely about real time collaboration.

Most of those ideas live on Google docs , SharePoint and notion and other tools. Am not sure how discord or slack solves the same ideas.

it was a hard problem to solve especially back then CRDTs were not baked in to any out of box large scale db, however it wasn't premature .

To me it always looked like an experimental product from which mature product took the good parts, no different from Gmail incorporating ideas from Inbox