Companies are collections of people, and these companies keep losing key developers to the others, I think this is why the clusters happen. OpenAI is now resorting to giving million dollar bonuses to every employee just to try to keep them long term.
If there was any indication of a hard takeoff being even slightly imminent, I really don't think key employees of the company where that was happening would be jumping ship. The amounts of money flying around are direct evidence of how desperate everybody involved is to be in the right place when (so they imagine) that takeoff happens.
