My friends almost one year old had croup just a couple weeks ago. He was hospitalized twice due to it and stayed 5 days the first time. It was very scary for her

In the past, daycare kids have had it. They stayed home for the first 24 hours after getting meds and then any time that it was too severe for them to be able to participate in activities. It's contagious so I'd encourage to disinfect. I'm the same as you and like for the kids to build up their immunity but there's a big difference between every day germs and illness germs. Disinfecting will help decrease the spread of any illness. I clean toys when needed but disinfect when any illness goes through