So what?

Yes, that's about 3 billion people. They use whatever they can afford. Usually that's whatever is very old, because new software doesn't run well except on very new hardware which is more expensive.

I recently wanted an MP3 player for an art project. Local stores don't sell mp3 players anymore, they only sell smartphones. So I bought an MVNO smartphone for $40. When I charged it up and tried to use it, I thought maybe it was broken, because it would take 10-30 seconds to load a settings menu or app. Nope, all these bargain carrier-branded phones are that slow. The hardware is [somewhat] old, but the new Android OSes run like molasses on them. It was like going back in time. Remember how Windows 98 would make your hard drive screech for a good couple minutes as it struggled to juggle the swap memory so you could open MS Word? That's the experience with most software today with "affordable" hardware even a few years old.

So using Windows XP is often the only choice, if you don't have a lot of money, like 1/3rd of the planet. (And it's not just the third world. 59% of American households with K-12 school kids don't have a working computer, or it works too slowly to be useful)