In the United States, I think that permitting, interconnection queue backlogs [1], and political efforts to protect legacy coal against cheaper competition [2] are the biggest obstacles.

That said, the US had its best-ever year for solar deployment in 2023, and this year is projected to be even better: https://www.eia.gov/todayinenergy/detail.php?id=61424

[1] https://www.utilitydive.com/news/grid-interconnection-queue-...

[2] https://montanafreepress.org/2023/06/03/the-battle-for-clean...