I really like the ‘Fullscreen (borderless)’ option, because it allowed you to alt-tab out of games without it crashing or playing up. However, some games didn’t come with that option, which is where Borderless Gaming came in handy. It removed the borders from games and made it fullscreen, just like the borderless fullscreen option other games have.
However, recently, Borderless Gaming is now no longer free. You have to pay for the release on Steam. You could download the source from GitHub and compile it, or you could download an older version, or you could download the latest version on the ‘releases’ page of the GitHub repository that came out 3 days ago (which defeats the purpose of having to pay for it on Steam if you can just download it for free there anyway), but I decided to create my own minimalistic version of Borderless Gaming, called FreeBorderless, because you don’t have to pay for it on Steam. Enjoy!