Same model, different device id. It happens.

No, that's a marketing issue. Different device id == different model, technically speaking. Hardware makers won't just alter a device ID for no reason at all.

There are tons more of device IDs out there that don’t work on Linux than those ones that do.

Perhaps, but [citation needed].

No, you can’t just use any random fingerprint reader which totally works on Windows.

First of all, no one is going out and buying random fingerprint readers - these are usually bundled as part of their laptop/desktop - in which case, it's the buyer's responsibility to verify Linux compatibility with that computer as a whole. You can't expect to pop Linux into any random computer, or connect any random peripheral and just expect everything to work automagically. I mean, it does happen, but that's generally with known good Linux hardware. Eg System76s, Frameworks, ThinkPads etc.

Also, even on Windows, a fingerprint reader doesn't normally work out of the box - you'll need to install the drivers for it to get it going (unless of course you're using a Windows build provided out-of-the-box by the system manufacturer). Either way, it's manufacturer's responsibility to create and upload drivers, and it's their responsibility to create a Linux driver. Otherwise it's up to the community to create it, in which case you're back to usual rule-of-thumb where you buy only popular hardware models with known good Linux support.