Yes, orange peel has always been present to some degree on just about every car. But how it is handled varies.
Coating technology has improved enormously since the '60s. Many years ago, if you spilled alcohol on Duco, you had a problem. The later lacquers were a bit better, but still had UV issues. Applicators got around these problems by laying down a heavier coating, to permit more corrections as the paint aged. Today's urethane paints are really durable. My body man didn't like the recent changes in some water-based products, but they haven't seen a problem with durability.
Paints are so good today, people forget how hard it was with silver paints.
Good urethane auto paint is quite expensive. The issue has always been how much paint a manufacturer is going to "spend" per vehicle. That affects how to deal with orange peel. Chrysler owners from the mid 80s into the '90s know all about not enough paint. They were too worried about it peeling off the car to even think about orange peel.
But as you move up market, you get the highest grade coatings, and more of it. That extra coating depth allows more margin for corrections, including removing residual orange peel.
Some owners of near exotics and exotics will spend four to five figures with top detailers to bring down the clearcoat to remove every last hint of orange peel. These cars do not have thin coatings. The cars look beyond incredible.
I had my detailer do that on a much lighter scale on our R129 when we got it. That car has the paint depth to do it. But I don't think I'd ever even attempt that with our '11 Chevy truck. The paint is very good . . . but there just isn't enough there for serious corrections. Like everything else, the more you spend, the more you get.
Corrosion resistance is more a matter of the panel content and prep than the coatings. You can chisel the paint off an old Volvo and it will take forever to rust. If you nicked a late '70s Honda, rust spread like the plague.