I still can’t get my head around why anyone would voluntarily use a touchpad when they can connect a mouse to their laptop

Connecting a mouse to a laptop is way less handy (no pun intended or wtv) than just using the built-in trackpad. Not only are the gestures nice, but using them isn’t bad at all, imo. External mice often need a mat, often have long cables that get in the way (though wireless is certainly becoming more popular), and in general take up more space, which kinda goes against the portability and readiness of laptops, mostly used in contexts where peripherals are not really something you can have.