I was surprised to see that my car's payload rating is 650lbs considering that it has 5 seats (130 lbs per person!), but then I remembered that these Google knowledge card results are usually wrong.
But it turns out the correct answer is barely over 1000 lbs, or ~200 lbs per person, which still seems surprisingly low. For reference, in the U.S., this is roughly the median weight of a 40 y/o male and also the average weight of an adult (20+ y/o) adult male.