I thought power storage was still a major problem (think overnight hours) as well as the U.S. grid not being able to handle such a variable load
Part of it is that, part of it is operating conditions. Solar works fantastically well...in space. On Earth it's a little more challenging. There are various issues of scale, as well, but that aside, the real world realities don't mesh well with the promises from solar manufacturers. Also maintenance becomes cumbersome. Good for solar panels? Lots of cloudless sunlight. Bad for solar panels? Dust. Guess what most places with lots of cloudless sunlight have....
You get the idea.
Hasn't stopped people from trying, and obviously not a zero sum game, but it's further from viable than most people understand. Even very smart people.