Property and sales taxes are also high.

I think one major problem is the number of government bodies with taxing authority:

https://www.illinoispolicy.org/reports/too-much-government-i...

Essentially, Illinois has a long history of corruption and political patronage that I find detestable.

sure, its not the first concern. but, if you're going to pick everything up and leave all your friends and family behind, don't you want to find someplace ideal (consider all your choices and all factors involved) ?