This is weird & bad for so many reasons. But what I focus on is:
1. I believe, morally if not practically, this tracking is *worse* than the old 3rd-party cookies. This is because 3rd-party cookies were a legitimately useful tech that could be misused for ads. This tech is *designed* to benefit advertisers from word go, yet is installed on *your* computer, like Malware.
2. Firefox is *worse than Chrome* in their implementation of ad snitching, because Chrome enables it only after user consent.