Please tell me you guys agree with me!

It was $300 so not cheap but because we have 2 cats and a dog that all drop ALOT of fur, and I thought a pen like this would be perfect for Ollie so when he starts to crawl he won't be crawling through all the animal fur and also has his own play area away from the pets. Anyway I showed my SO and he thought it was stupid to buy something like that because of the price (fair enough reason) but that it's also stupid to "cage him up" then he said that Ollie needs to build an immunity so crawling through the animal fur won't hurt. That's why I want everyone else's opinion because I don't believe that crawling through/inhaling pet fur is building an immunity, it just disgusting and can cause Ollie to choke or get sick. There's a big difference between letting your child build an immunity buy say playing outside in the mud compared to sucking up pet hair off the floor. I couldn't find anything online to prove my point to my SO but maybe if you guys agree with me I can show him I'm not the only one who reckons that he doesn't need to crawl freely around the house through pet fur to build an immunity.