I agree. I remember when I bought a refurbished ThinkPad T430 to play with back in late 2016; it came with Windows 10. The interface looked gaudy on the laptop's 1366x768 display, with all of its oversized elements. It seems to me that Microsoft has a penchant for UI designs that consume a lot of vertical screen real estate (i.e., the Microsoft Office ribbon). On the flipside, I've had the opportunity to use Windows 10 on a 4K display at work, and it looks much better on it. It seems to me that Windows 10's UI is designed for high-resolution displays, but the problem with this assumption is that there are a lot of business laptop users out there making do with 1366x768 displays. The old-style Windows Classic or Windows 7 UIs with their conservative use of screen real estate would fit perfectly with these displays, but unfortunately these themes are unavailable in Windows 10, and it still wouldn't address the problem of applications written using Windows' modern UI guidelines.

macOS still looks good on my 1440x900 2013 MacBook Air, and I like how the Cinnamon desktop looks on my ThinkPad T430; I use Linux Mint on that ThinkPad now.