We’re rapidly reaching the point where 1080p PC gaming is considered “outdated,” and many players are looking to upgrade. Most people likely assume 4K is the natural next step; that was the upgrade path for most TV owners, after all. However, 4K monitors are more expensive and harder to come by than 4K TVs, so many PC builders opt for 1440p displays instead.
Yes, monitors can be pricey, and they are also items that can be used for many years, so are not something you just replace every year or two. It is also true that as you up the resolution, as well as refresh rate, then your CPU and/or GPU has to work harder to achieve a smooth performance.
Other practical things to also consider with a new monitor are whether you require VESA mounts (to mount on a wall or above a desk on arms), the types of ports your graphics card supports (don't just default to HDMI), and the refresh type that is compatible with your GPU card (otherwise you may not be able to take advantage of the monitor's peak performance). So I always consider these basic requirements first, so as to narrow down what I need to consider choosing. A simple spreadsheet really goes a long way!
For me personally, I'm still fine with my three 1080p, but my newest addition was an upgraded refresh rate to 144 Hz.
See Should You Upgrade From Your 1080p PC Monitor to 1440p?
1440p offers better detail than 1080p, but the benefits aren't universal.