There are plenty of people who worked on AI (as graduate students, as ML researchers at hot startups for self-driving cars, as pure researchers or supporting engineers at Google or Facebook, and many other places), and then left because once they saw how limited the research was they lost hope it was going to happen before they died.
Also while I fully understand and appreciate the necessity of OpenAI abandoning the 'open' part, it says a lot about who is going to benefit from this technology when you have investors who want to make money. It's just ironically poetic in this instance.
I honestly don't see any possibility of truly "wide-spread benefits for humanity" if AGI is achieved anytime soon. Current state of humanity when it comes to how we treat each other and anything akin to species-level awareness and collaboration is only barely better in recent history than the dark ages. If a group of people gets access to an AGI, I think it will very quickly result in a bit wider group than that having their lives prolonged, no disease, no lack of resources and practically infinite wealth, and everyone eventually being either rid off, or allowed to live in far-away slums and left to die off.
Also while I fully understand and appreciate the necessity of OpenAI abandoning the 'open' part, it says a lot about who is going to benefit from this technology when you have investors who want to make money. It's just ironically poetic in this instance.