Another one of such thing: please try to scroll on your site using a mouse wheel from time to time, even if you're normally using a touchpad (from your laptop or an external one)! Lot of fancy homepage with scroll animations are awful on anything that isn't scrolling as smoothly as a MacBookPro touchpad. Example: https://www.apple.com/ipad-pro/ is horrible to use on anything that isn't a mobile device or a Mac.
Developers (seemingly a lot of them?) use a touchpad as their primary input device on a regular basis? I guess this is an example of being in my own bubble, but I can't stand touchpads. I've used the touchpad on MacBook, like, twice in 2 years.
One demographic I would expect traditional mouse usage from would be gamers. When I play a first person game I always use my trusty old intellimouse. Otherwise, I use the trackpad unless I'm simultaneously using my mechanical keyboard, but if my keyboard had an attached trackpad I'd probably be using that. But mousing in general just isn't a very important to my workflows and trackpads work just as well as mice for nearly all tasks. Arguably they work better for some since you don't have to move your hand far from the laptop's keyboard to use the trackpad, while using a dedicated mouse means taking your hand completely off the keyboard.