I did 1099 work while living in TX through Jun'21. I then moved to Chicago, IL where I am a student (will live here for the next 2 years). Do I file as TX or IL resident?

If you're a college student attending an out-of-state college, you'll probably need to file a full-year resident return for your home state and not the college state unless you have a permanent address in the college state and have established residency in the college state. If you're a nonresident student and had a job or other income in the nonresident state, then you'll need to file a nonresident state return.

Texas has no state income taxes so there is no concern about filing a tax return for Texas. For federal taxes, you use your current state of residence where your current address is.