Can you share any insight about how an Indian CA became the preferred vendor for US universities despite the existence of LetsEncrypt? I know this is kind of a dumb question.

I had a friend who worked in university IT and I got the impression that there was a strong desire to use "supported" products (in general, not just certificates) even if it cost money and was worse than free alternatives.

Interestingly, InCommon used Sectigo prior to this year. I'm guessing eMudhra costs less.