I'm in Chicago grocery stores almost daily and compliance with masks is 100%, employees and customers.
Viewing outside diners gives another picture (no masks), but these folks are (a) outside and (b) eating. It's not the whole picture by any means.
I would say from the times I've been in various stores(and live in Chicago myself), that it hasn't been 100% compliance with mask rules. Weirdly enough, at times I'll see occasional employees at various places not wear a mask. Not often, but a few times I've noticed that, and it surprised me. The vast majority of employees I've noticed in various stores and places do wear them, and compliance is for the most part pretty high and well observed with customers in stores. BTW I am not ripping on people dining or drinking at restaurants and bars, where I can understand in those situations(while eating or drinking) taking off your mask.
Restaurants were take-out or delivery only until late May, then outside dining only until late June, and now indoor dining is allowed at 50% capacity, 25% only in Chicago. Masks are mandatory in stores, offices, etc. and I haven't seen anyone (employee or customer) maskless in a store since masks were required. Some places are checking temperatures on arrival and others aren't. The Lakefront trail was closed for months, outdoor facilities like the zoos and botanic gardens were closed until recently, and the Riverwalk opened up fully only today.
I know in Chicago(at least up in Uptown, Edgewater, and Rogers Park when I test rode biking or walking through lakefront parks before their reopening), that most people were ignoring the lakefront closure rule, and just walking into lakefront parks pre-June 8. At least pretty much all the people I saw in lakefront parks, were respecting social distancing. Maybe an unpopular opinion to some, but to me(since I bike a lot myself) I always thought Lightfoot overreacted a little bit by closing the lakefront trail and 606 trails completely, for a period of time. To me, I think she should've at least kept those trails open for runners and bikers, if nothing else. Using the rule Seattle did for their parks during COVID, by instituting a 'keep it open, keep it moving' rule where as long as you were using the trail and not loitering, that you could use the trail. Though later on starting on June 8, Lightfoot did finally reopen those 2 trails, using the 'keep it open, keep it moving' approach(didn't say that phrase, but essentially Lightfoot was doing the same as Seattle w/their parks by allowing trails to reopen). To me though, closing the lakefront trail and 606 at 7pm, seems a slight bit early to me. Heck, I'd be okay if she said those trails would be open till 9pm!
You also mentioned zoos and outdoor gardens. As I remember, Brookfield Zoo was supposed to reopen this month, but that supposedly you had to have a reservation in advance to go there. Chicago Botanic Garden and Morton Arboretum were doing the same thing, for now. I think I heard Lincoln Park Zoo was supposedly going to do the same thing, but that for now you only could visit that zoo and do a reservation to visit if you were a member? In late July, I heard LP Zoo was going to open up reservations to even non-members.