A lot of it is software. When the Chromebook guys were just starting out they wanted a Mac style touchpad, but discovered you couldn't buy one on the open market. They had to do a ton of custom work on drivers to try and get close to Apple's work. There's a lot of subtlety to palm rejection, scaling, haptics, etc.

I think it also helps a lot that the OS (or at least a version of it) was originally designed to work with a one-button mouse.

The two-fingers-tap for right click works great on the various Apple trackpads. Much better than the same gesture on my expensive Dell Precision. Both the two fingers gesture and the click on the right side of the trackpad, which is infuriating. I really don’t think the OS supporting one-button mice explains the difference in reliability.

So is it software in the OS, or is it firmware in the touchpad itself? Software in the OS should be very easy to improve, but it seems like it should be very device-specific. Firmware in the touchpad controller is another matter.

I feel like on other laptops everyone is optimizing for specs/price and specs don't include quality of life features like a good trackpad. Sure, it would be nice to have a good trackpad, but chances are your customers are going to buy a cheaper laptop with a worse trackpad from a competitor.

there are some coming out, the lg gram for example, has a haptic touchpad