Invest in really good ventilation! A lot of apartment shower vents just kinda vent into the wall, with too-small ducting that is easily blocked. I had a contractor get into the walls and put in new wide ducts, making sure they went all the way to the outside vents and were locked on, put new screens to keep bees out, and installed new vent lights with better motors and set them to High. Now I can get out after a hot shower and see myself in clear mirrors, and mildew is no longer a problem. Another thing about OP's setup, it's baths only, and that means less steam in the first place.