From what I have read its simply not how Google works on the inside. They have all the best programmers developing new "products" which then get tested live. If a product wins great, put the best on something else. Maintaining existing products outside of the core search and ad's is seen internally as a menial job, and managers focus on keeping maintenance costs low and quiet new ideas.

But yes, Hangouts was amazing at its peak. I could group chat, video chat, send MMS like posts, connect it directly to my google voice and more. They should have kept working on it.