Apple does it because they don’t have a vested financial interest in internet-wide tracking.

Google does.

And while Mozilla does too because the vast majority of their funding comes from Google, it’s more pertinent that they don’t have the market share to pull this off. Firefox would just stop working on major websites if they did this.

Doesn't that just move the goal post though? Instead of using your GPU vendor for the fingerprint they can just hash the output canvas after they a bunch of odd rendering calls, getting a hash from the quirks of your graphics driver and GPU hardware.