Nobody at my company uses an iOS device. I'm the only one not on Windows and I use Ubuntu.

If you look at the global marketshare, Android dominates iOS.

The point is that I can test on Windows without a Microsoft device or giving money to Microsoft to install Windows somewhere. I have no way to test anything on iOS or even Safari.

Android dominates iOS in terms of market share, sure. And testing for Android is a much worse nightmare.

When I test my site in Safari in an iPhone and an iPad, I’m fairly sure it works on every other reasonably recent (think three years old or maybe even older) iPhone or iPad. Android? Well, there are so many browsers on so many different Android versions, am I supposed to own a fleet of devices, each with a fleet of browsers? (Plus the fact that I can’t really justify purchasing a flagship Android phone for testing, so I only have a crappy one and I hate every second with it; that’s more of a personal thing.) So in the end my attitude with testing on Android is don’t even bother.

You are saying like if almost 1 billion of WIndows 10 users aren't huge installed base?

Well they don't all use Edge. The majority of them use Chrome!

Exactly. Everyone on iOS uses Safari (either direct or as underpinnings for "Chrome", "Firefox" etc browser interface someone might want to put on top of it)

Maybe not Windows phones but definitely Android phones. Because Edge is available on Android and seems to be quite popular. And that is a huge market, bigger than ios'.