Windows laptops aren't inherently more upgradable or powerful than Mac laptops, and especially with the advent of Windows 10, forced upgrades are just as much of a potential problem as they are with Mac laptops. Windows laptops also aren't inherently better than Macs for gaming. I have a pretty well tricked-out Dell laptop that I use for work, and I could go to the Apple Store right now and build a MacBook Pro that would blow it out of the water, specs-wise.
There are an enormous range of laptop products in the Windows space, and it's quite possible to buy a Windows laptop that's not upgradable, underpowered, and lousy for gaming. In fact, that's a lot of those bargain laptops you see advertised.
It really boils down to looking at the specs of individual laptops and seeing how well suited they are for what you want to do. If you want to do a lot of gaming, you can do that on either platform, but you'll probably need to do a custom build to get a good-enough video card, and that will drive the cost up. If you're interested in Apple, unless you're wanting to do a lot of gaming or high-end creative work, most people can get by very nicely with a MacBook or MacBook Air, which start around $1000. If all you're going to do is web browsing and running Office apps, a MacBook Pro will be a lot more computer than you need.
It also depends on what other devices you have. If you've got an iPhone or iPad, there are definite advantages to staying in the Apple ecosystem.