Basically the same reason you're using mosaic + the ability to change what exactly is being done. I use it to map 'hyper'+key (where hyper is the equivalent of ctrl+cmd+shift+option and is assigned to control, capslock is assigned to the original control functionality) to move windows between screens and on their own grid. Effectively I just didn't pay for mosaic-like functionality. I have better touch tool, but I never liked having to drag to snap and had hammerspoon implemented already.