Modern emulators come with various features like hardware acceleration, adjustable resolution, high FPS support, controller support, etc.
The easiest way to play Android games on PC is by using an emulator. Finally, you have access to much more storage space on your PC compared to the internal memory of a phone. And the best part about gaming on PC is you never have to worry about your phone overheating or low battery. Pretty much any shooter that you play on your phone will be much easier with mouse aim. There are a ton of Android MOBAs like Arena of Valor and Mobile Legends, which could really benefit from mouse and keyboard controls.
Or a gamer who wants to play PUBG on the big screen.
Maybe you’re a developer trying to test out some new apps. There’s plenty of reasons why someone would want to install Android on their PC.