Maybe it's just time and continued development on libinput, but the differences I found are:

Two fingered scroll works by default

Sensitivity/Acceleration curves basically match OSX out of the box

Right click on two finger tap is easily enabled and feels good

Support for multi finger swipe (3/4 fingers) easily enabled and feels good

Palm detection is MILES better (I have huge hands and this is a serious problem)

---

Each of those was a serious issue 3 years ago trying to get things working through xinput (although again, I migrated to wayland about 1.5 years ago and have never looked back so maybe it's better now)

X and xinput give folks a TON of options, and in certain situations that's great. But most of the time (all of the time in my experience) it led to bad defaults and consistently broken settings after upgrades.

I genuinely enjoy the zero configuration approach Wayland has taken here with libinput.

I'm on a mac for work, and while I really disagree with Apple's philosophy, I can't argue that they provide a simple and fantastic touchpad experience. I get that by default on my current setup and it feels nice.

I genuinely enjoy most aspects of system management, but trial and error editing of magic numbers in an xorg conf file for my touchpad just sucked.