Those 85s look incredibly similar to me. I see about the same amount of difference between the 80s barges and the 2019s honestly. Corporate design languages are still very much A Thing. These vehicles in the same segment look the same because they're subject to the same economic environment, regulations, and customer preferences/expectations. Just like all vehicles have always been.
I think there's the same amount of copycat/variety now within a given segment as there ever has been. It's just that there aren't as many segments now. You used to be able to get a lot of the same vehicles as a 2 door, 4 door, wagon, and convertible. You used to see a lot of vans. Now, many of those bodystyles are unavailable and/or unwanted by buyers. So because you don't have as many sports cars and convertibles and station wagons and vans, all of those buyers have moved to crossovers and trucks. which makes it seem like they're all the same now even if they've always been mostly the same within the segment.