A bunch of work happens for things like wifi and cpu because of Android and ChromeOS.
But, the number of professional paid developers doing "desktop Linux" drivers is probably fewer than 10 right now [0].
The number of full-time paid developers on "desktop Linux" itself is probably under 100? ... probably more like 50 honestly.
Drivers are of alpha quality (using your definition) because they are not written by the manufacturer. The reliability of drivers is down to the lack of availability of information. The bottom line is that the lack of access to information about how the hardware works means it's hard to make reliable drivers.
Your trackpad example is perfect because AFAIK synaptics had to reverse engineered.
Microsoft doesn't write drivers, the hardware vendors does. And Microsoft runs a test, if the hardware works then it passes the test and gets a sticker on it's butt. HP can only ship hardware that has the sticker. This outsources the cost to the manufacturer and the testing to the OEM.
Whereas, in Linux land those economics don't apply.
I get your points but if you actually want to use desktop Linux then this is one area where you have to go with the grain - buy a PRELOADED certified system because that's going to be built from the smallest set of hardware that the vendor knows is compatible.
[0] meaning there is no-one paid to work on monitors, there is no-one paid to work on that trackpad. What is being paid for is so that Android or ChromeOS can work.