Additionally, touchscreens can be less accurate and less precise than traditional trackpads and mice. This is particularly true when it comes to fine-grained tasks such as photo editing, where precise cursor control is essential. Since there are devices out there to provide a better experience; making a subpar touch screen just to add fingerprints, can make life worse for the MacBook user.
Furthermore, Apple has always been focused more on MacOS user experience in a desktop format rather than a mobile format, which is why touch screens are not necessary for MacBooks.