Privacy is not a binary state, but rather something of a spectrum ( and partially a reason as to why Google and others try different avenues for siphoning data ). Every little bit helps a little bit depending on your tolerance and skill level. I genuinely do not expect my mom to run FF with appropriate plugins from a scrubbed VM each time she wants to check something. But I can give her some sane defaults instead.

I agree with your general point, but ignoring an issue just because there is no 100% solution is not reasonable either.