My understanding (and I stand to be corrected on this) is that it was struck down by the trial court, but has been appealed, and is working its way through the appeals process.I have a couple of friends from the Chicago area that are gun enthusiast. According to them, the FOID is in the courts but not struck down yet.
I do recall hearing that Chicago's virtual ban on firearms ownership was struck down (maybe when Dana Loesch was on Jack Carr's Danger Close podcast last week? I know she talked about the guy who fought and won that in the courts), so it's probably not correct to exclude Chicagoans from the population of Illinois gun owners.