This is kind of interesting: https://www.bts.gov/content/estimated-national-average-vehic...

Exhaust particulate per mile has plummeted over the past couple of decades! By comparison, EPA stoves put out a couple grams of particulate per hour.

But, it seems like it's not apples to apples, because brake dust is metal dust, whereas wood smoke tends to be mostly organic compounds. Maybe the body is better at dealing with organic wood smoke compounds? We've certainly been heavily exposed over many generations.