Can anyone explain this process

Hello J. Windows Update does provide driver updates, however it does not provide all device drivers and does not keep all device drivers up to date and is not reliable when it comes to third-party device drivers. Microsoft prioritizes stability and compatibility with driver updates and only critical and WHQL-certified drivers are automatically pushed to a user's Windows device. Most people including myself are overlooking many important performance, or function-specific drivers that accompany a newly purchased device like graphics cards, audio chipsets, gaming peripherals/controls, etc., will need to be downloaded manually from the manufacturer's support site or installed using the manufacturer's separate driver manager application. If you just purchased a Windows device and managed to turn it on and somehow connect to the Internet sooner or later you will likely find yourself frustrated that Windows or your new device isn't working as expected even after all the preliminary updates, and you will likely run into instances of having to go in search of a driver update.

To find or keep your drivers current, you should consider the following suggestions:

1. Check for Optional Updates under Settings > Windows Update > Advanced Options.
2. Use Device Manager on your computer to manually update drivers.
3. Check out the manufacturer's support site for latest drivers and/or use the manufacturer's official driver manager application.

Here's the reference: Automatically get recommended and updated hardware drivers
Best regards,