> I don't know much about forever chemicals. Is there the same level of evidence as we had for lead?

No. We have observational data in humans (which is problematic for drawing conclusions, since PFAS contamination tends to correlate with industry and population), and animal models, mostly in non-mammalian species.

As you correctly note, lead was known to be toxic since long before leaded gasoline -- the "question" was more about the delivery mechanism (auto exhaust) than the toxicity of the element itself.