I built a tracking blocker detector about six or seven years ago and found about 20 some odd percent were blocking trackers based on my guess.
It was pretty rudimentary. I just made calls to ask if certain functions from GA and GTM were defined and if the function was undefined, I assumed they had been blocked from loading. Once I knew the status of each, i loaded a 1px image and added a query string with the results of the test.
I didn’t count any request where JS was not evaluated, assuming most of those were bots.
Anyway, my results were roughly in line with what more sophisticated people were finding back then. So it looks like it has at least doubled.
