Hah! I used to embed invisible pixels for our marketing department decades ago.

This should automatically qualify one to lose their internet privileges. Not just the fact that you did it, but your cavalier attitude towards it with the lack of regret for having done it

I actually agree with you. However, I plead that it was novel at the time, used ineffectively by a tiny marketing department, and not anywhere near this spy level capacity achieved today.

With that method, you won't be able to distinguish between the many different devices using the same browser at same resolution behind one IP.

In the era of CGNAT that means you now only know which city I'm from and whether I use Chrome or Firefox. People mostly use browsers in maximized and resolutions are relatively standardized nowadays.

Compared to the data you get from canvas and webgl, that's much less unique.