Right but say the mouse is a constant 1000hz. To get the most recent sample on the screen as quickly as possible you either need the entire rendering pipeline

Right but say the mouse is a constant 1000hz. To get the most recent sample on the screen as quickly as possible you either need the entire rendering pipeline to run ridiculously fast (the 2000 fps example), render just in time before vsync with impossible accuracy, or bypass as many clocks and buffers as possible and blit the cursor with hardware magic. There’s a reason it’s still done this way after so many years of advancement