3.8 gpa, Test optional, UIUC college of Liberal Arts chances [WA resident, brain and cognitive science or sociology]

It’s hard to know whether or not it’s a disadvantage (at some schools they say below 50th percentile don’t submit, and others say anywhere in the middle 50 is fine), but regardless, it’s done now so no point going on about “should have” - either way I can’t see that it would have swung the decision. You said your Ap scores were good so I assume you submitted those?