The touchpad on my current gen Dell XPS 13 is superb on a stock Ubuntu install. I'd love to know how much of the "bad touchpad" reputation that Linux has is down to low quality hardware versus software support.
Have you tried a Mac touchpad? I use both a Dell XPS13 (Ubuntu from factory) at home, and a MacBook Pro at work. The Mac's touchpad is miles ahead... and that's even after I spent a couple of days messing with libinput settings to make the Dell's touchpad more acceptable (it's fine now, just not really close to the precision of the Mac's touchpad).
Most likely its cursor acceleration. macOS dynamically adjusts the cursor movements based on the user swipe speed which makes it feel both precise and fast.
Last time I used Linux on my MBP, libinput was more... linear.
It's really quite difficult to quantify what's actually different. It feels really precise without being "flicky", using it feels very natural and you sort of forget about the touchpad and just will the cursor on the screen to do as you wish.
I've always struggled to articulate why I prefer the MacBook's trackpad to every other trackpad I've used, and I think you've hit on something with that last sentence. It feels so natural that I really just don't ever think about it, my brain skips straight to the actual interface I'm using it to manipulate.
I get the same feeling with high vs low quality touchscreens (e.g. my phone vs some ATMs), and especially with gaming controllers. With a good, ergonomic controller I sort of forget about the shape and weight of the controller in my hands after a while; my entire sense of it narrows down to the buttons/triggers/joysticks.
I have the XPS 13 9350 and i like the touchpad as well. There‘s always room for a little improvement but during daily use it‘s not that i‘m annoyed by the touchpad. Not at all.