Yes, they did; and Oldsmobile shut down in 2004. And since 2001, Chrysler no longer makes Plymouths; and since 2010, Ford no longer makes Mercurys.
Cadillac makes SUVs, and Dodge no longer makes pickup trucks, since Ram became its own division in 2010. Truly, the times, they are a-changin'.
Oh, yes. Japan is the biggest automaker in the world, what with Toyota, Nissan, Subaru, Suzuki, Mitsubishi, Honda, Mazda, Acura, Infiniti, Isuzu, and Lexus. The only brand they've had go defunct in the last 40 years has been Datsun.
The United States is now only the
second-largest carmaker in the world. And you see as many, if not more, foreign brands on the roads these days as you do American brands: KIA and Hyundai (Korean), Audi, BMW, Mercedes, and Volkswagen (German), and every so often, even a Fiat (Italian) or a Mini Cooper (British).
It's a different world.
I, myself, in the last three years, have replaced my GMC Yukon with a Toyota Corolla, and replaced a Chevrolet Impala with a Toyota Prius. They're more economical, and frankly, better-made cars than the GM models they replaced, in my own humble opinion.
Yeah, the Pontiac "delta" was in vogue during the mid-1960s, when I remember seeing them on hubcaps when I was a kid. Of course, all those car brands would change their logos about every 15 years or so; it was like an unwritten rule. About the only one that's never varied has been Chevrolet.