Is there an easy way to obtain all of the Boot Camp drivers hosted by Apple by using Windows, and not relying on macOS?
You can until the 2015 model year. This is when Boot Camp Assistant application starting installing Windows without the use of a DVD or USB flash drive. Basically, the previous answer explained the drivers can be found using the links provided on the Apple webpage Install Windows 7 on your Mac using Boot Camp. These downloads are in the form a zip files which can be unzipped by Windows or macOS. As I already explained, the Snow Leopard ISO must be mounted on a Windows machine in order to access the Boot Camp files. If you mount the the ISO using macOS, the you will get the Snow Leopard files.

You should also note that the Boot Camp Support Software (Windows Support Software) includes Apple Update which often downloads updates to the the Boot Camp Support Software. This no longer works with many of the older versions of the Boot Camp Support Software. However, when you install other Apple Software, an updated version Apple Update may be installed. These updated versions have been know to download updated drivers from Apple, but rarely update Boot Camp itself. Also, Windows Update will also download updated drivers for Macs.

The previous answer included a BASH script/function which produced a list of URLs based on a given Mac identifier. When one of these URLs in pasted to Safari, a .pkg file would download containing the .dmg file, which contained the Boot Camp Support Software. I realize this requires a macOS, but the same thing can be done in Windows by using Microsoft Edge and some free third party software.

For example, installing git by default provides a BASH window which can execute the GetPkgUrl function. 



The .dmg file can be extracted from the .pkg file by using Easy 7-zip.



After clicking on the OK button.



The result is access to the Boot Camp Support Software, which can be extracted from the .dmg file by using Easy 7-zip.



Did not check every model identifier, but for the iMac14,1 (2013) through iMac19,1 (2019), there is only one .pkg file per identifier. I theorize this is probably true for all 2013 and newer Macs. Therefore, it may to be too difficult getting the Boot Camp Support Software for the latest model Macs. 

I realize what you are really looking for used to exist. When OS X was delivered on DVDs, the current version of the Boot Camp Support Software was included on the DVD. This covered all model Macs up to the release of the DVD. After Apple starting eliminating optical drives starting in 2012, there was a website providing links to the zip downloads. However, by 2015 Apple was switching from websites to the use of the Boot Camp Assistant to download the Boot Camp Support Software.