Sure they do. The 2013 Chromebook Pixel for one.

But yes, it's hit or miss. My Dell M6800 'portable workstation' has an abysmal touchpad (really, what were they thinking?), but then, since it is way too heavy to actually reside on the lap, I use a mouse (which in any case is more precise) there. So the proper question is then, why did they bother with one at all?

Otoh, the cheap lenovo ThinkPad 11e has a surprisingly good one.

Does any other manufacturer produce their own? I think the major issue is that other companies are integrators of cheapest bids for components, not computer companies.

Apple isn't producing all of the components in their laptops either.

It's a bigger picture thing. Apple has some vision for what a good laptop is like, and has been iterating for decades to achieve that. Each new generation brings some amount of change (including some real failures like the Touch Bar and butterfly keyboard).

Absolutely any other manufacturer could achieve that if they were willing to focus on it, iterate, and not give up. It would take some time, but it would happen.

Not all, but many and especially these where existing parts can't match the UX. Lenovo or Dell doesn't care, they just buy from the lowest bidder.

I've seen some close ones on higher end chromebooks. The Razor laptops are also close. The clicking motion is a bit off/different on many, but there are some that are very close generally speaking. I get what you mean. Currently using an M1 air for personal laptop, work issued is an M3 pro. My next personal laptop will likely be a Framework AMD 13" running PopOS.