Until you get in an accident, and then you’ll care (or be dead so you won’t). Safety has come an awful long way in 35 years. And I actually think “most people” do give a shit about their families not dying preventably
Sure, a lot of advances in safety were made in the 28 years between 1959 and 1987, so your car won't fare as badly as the Bel Air, but there were plenty of other advances in the 22 years between then and when that Malibu was made in 2009, and likely quite a few in the 13 years since.
It's a free country, so you can take your chances if you want. I wouldn't rate them that highly though, FWIW. ¯\_(ツ)_/¯
Suburban vs Smart Car, sure, you "just" kill all the occupants of the smart car, and get some whiplash since you don't have headrest and possibly head injuries, since you might not have a shoulder belt.
Suburban vs modern sedan, truck, SUV, semi -- you're dead.