There's no point reinventing the wheel, so there's no point making your own GetClosestPlayerToCursor function when Aimwork exists. Aimwork handles everything for you, in an optimised way. It's likely to be far more performant than anything you can make yourself. The goal of Aimwork is to handle hundreds of players with mininal (as low as 0) FPS impact. This isn't the benefits though. There are many more:

• Insane Optimisations

  Aimwork has been written from the ground up to be as optimised as possible

• Reputable

  The developers behind Aimwork are well known in the community, often given the title of the first person to make a Da Hood silent aim in 2020

• Free and Open Source

  The code behind Aimwork is one of the most high quality Roblox scripts out there. Not only that, but it's free and open source