My employer (a mid-sized tech company) had a policy that employees could access corporate Slack, email, etc. from personal iPhones but not personal Android phones. I think it was for security reasons.

I was using Android, but I needed mobile phone access for on-call shifts. The company gave me a choice of either replacing my Android with an iPhone (and they would partially reimburse the cost); or, they would issue me a corporate iPhone, and I'd have to carry both phones when I was on-call. I picked the first option and switched to iPhone.