The problem is, if you are running a marketing database of millions and and millions of distinct IDs, you have to get into very esoteric fingerprint factors. Anytime you have a driver update or switch devices, you lose the connection in the data.

https://medium.com/slido-dev-blog/we-collected-500-000-brows...

Can it track you for a bit and show you some ads? A little bit. But compared to a tracking pixel it is not even remotely as reliable.