Indeed it is. But this is also calculated based on monthly page views, so it only really covers devices that are used in that month.
There’s a non-trivial amount of Windows users that have a dusty laptop that they only pull out when they need to write a document or fill in a form that they got emailed, and will otherwise do all their computing on their phone.
My guess would be that Mac and Linux have fewer of these types of users? But who knows. I have a couple of Linux devices that I almost never use 🤷♀️