The tilted cursor that we are familiar with today serves a purpose beyond just aesthetic design. It was originally created by Douglas Engelbart and became the standard cursor when the XEROX PARC machine was built. The tilted arrow shape was found to be easier to recognize on low-resolution screens compared to a straight cursor. The angle of the cursor also helps guide the eye down the length of the pointer, similar to perspective drawings, and allows for easier calculation of the click position. Additionally, the tilted cursor provides a sense of pointing and is more easily found due to the popout effect in our visual cognition.
https://ux.stackexchange.com/questions/52336/why-is-the-mouse-cursor-slightly-tilted-and-not-straight