That's a shame. I recall last summer seeing some dedicated and well-wetsuited people swimming much closer to town, along the concrete shoreline to the north of Ohio Street Beach.
Swimming in the Great Lakes is not dangerous at all. They account for 14 drowning deaths per year out of 4500 across the country. That's a quarter of the annual U.S. drownings in the Atlantic despite having more U.S. coastline.
https://www.chicagoparkdistrict.com/parks-facilities/beaches
Swimming in the Great Lakes is very dangerous, especially if you are not familiar with the behavior of the lakes.
https://glsrp.org/statistics/