Gestures like pinch to zoom or swiping photos are easier with touch. Drawing a shape or writing a signature are another thing.
Multitouch is something a mouse can’t do at all. Macs have quite a nice set of gestures that can be used with the touchpad. A touch screen could use similar gestures.
For laptops touch screens are useful. Especially on convertible laptops, that transform into a tablet when folding over the screen completely. Also when you’re using it with more than one person at the same time.
For desktops, I don’t really see much of a benefit. Apple’s touchpads are pretty nice for that use case. I used to have a mouse on the right and a touchpad on the left of my keyboard.
Apple has completely failed to build a great convertible laptop for many years now. Windows laptops do it somewhat okay, but this is the product category where Apple could actually build something great. Apple Pencil on a convertible MacBook would fly off the shelves.
Since Tim Cook’s reign started there has been little vision regarding product design.
Apple should go beyond iOS, iPadOS, macOS to a unified operating system with an adaptive UI. I want to connect my phone with an M-series chip inside (or watch) to a thunderbolt hub and have a full desktop experience. iOS/iPadOS are too neutered. macOS is too neglected. VisionOS is a dead end toy.
I don’t want synchronization between four devices, I want one device that does everything and connects to various peripheries.