Website sends a 2.3MB (gzipped) json response for a dropdown and it's making my browser crash. Is this normal?

I'm trying to sign up for a site and everytime I select my country in a dropdown menu, my browser slows down. Then, after selecting my state and attempting to select my school, my browser completely freezes for about 30 seconds.

I did some investigating and found a request with a compressed size of 2.3MB. The request contents is just a massive list of, likely, every college in the US.

It seems to me like the site is trying to render the whole list in the DOM as dropdown options. Is this a case of terrible optimization? Or is my device at fault?

If anyone is curious to replicate the issue, navigate here, then select any course, click start/sign in, and finally, select United States for the country.