I appreciate your effort in doing the work and putting the chart together :)
You fairly disclosed how it was all generated, but sadly not everyone will read that. A lot of people are going to look at that chart and their conclusion will be "Wow, Firefox is like a tenth as private as Brave!" - which you and I both know is not a true statement at all.
Even if people did read it, things get saved and shared out of context all the time, and before you know it this chart is going to pop up in some Discord argument as evidence for why Firefox sucks just as much as Chrome, completely divorced from your comments or any reference of where the data came from - the source website URL isn't part of the image either.
I guess that's the danger of visualisations. Data Viz can paint a complex picture clearly in an instant, we just have to make sure its painting the right one.