Chicago local search is split between the city and a large suburban ring: Naperville, Evanston, Schaumburg, Oak Park and the towns beyond them. Service businesses usually need service-area pages and a Google Business Profile that reflects where they work, not just a downtown address.
For B2B and ecommerce companies headquartered here, the bigger lever is often technical SEO and category-level content. A generic "Chicago SEO" page will not outrank a national brand for a product term, and I will not sell you that promise.
The closest local proof on this site is a Dublin phone repair shop that went from 4 to 84 organic clicks a month after a Wix to Next.js migration and local SEO rebuild, not a Chicago client. I use it because the model is the same: one business, a real service area, and Search Console numbers from matched 28-day windows.
Chicago splits into three search markets, and most businesses are only in one of them. The city: neighborhood searches in Lincoln Park, Wicker Park and the Loop, where Map Pack competition is dense for restaurants, clinics and professional services. The suburbs: Naperville, Schaumburg, Evanston, Oak Park, Aurora and Joliet each have their own Map Packs; for trades and home services, this is usually where the volume and the jobs are. National product searches: Chicago has a large manufacturing and B2B base whose buyers search for the product or the part, not the city.