From what I can tell, window managers is by far the largest category of Mac apps. I regularly see new window manager apps on r/macapps and simple searches can show posts listing a whole bunch of different ones. I was very overwhelmed with the list and downloaded several to try. Months later, I'm not just using Rectangle free version to show windows on the right or left half of the screen, either full-sized, half, or 1-2/3rd. Only a few different hotkeys for position and sizing windows. I only have 1-2 windows focused at a time and have hotkeys set with Hammerspoon to switch between frequently used apps. I feel like a lot if not most of these apps are for fine-grained control and niche features which the vast majority of users would never need.