Because the ability to influence others is more important than 1 or 2 standard deviation in more intelligence.
However if we are talking about 10x more intelligence, then that'd be a whole different ball game.
Check Alpha Go -> Alpha Go Zero. Gaining orders of magnitude in capability only with slight change to the model, along with a lot of more resource (we can easily throw 100x more compute and data to these models if someone seriously wants to and don't care about ROI. Or maybe if AI starts to be hugely profitable, 100x in investment is almost a rational outcome) is not uncommon in AI research.
However if we are talking about 10x more intelligence, then that'd be a whole different ball game.
Check Alpha Go -> Alpha Go Zero. Gaining orders of magnitude in capability only with slight change to the model, along with a lot of more resource (we can easily throw 100x more compute and data to these models if someone seriously wants to and don't care about ROI. Or maybe if AI starts to be hugely profitable, 100x in investment is almost a rational outcome) is not uncommon in AI research.