Why do all cars look similar/same/cloned now?

Wow!
I was just going to type this kind of response!
Look at the cars of the '20s, they all look the same.
The '30s? yep, the same.
'40s? '50s? '60s? '70s? '80s?
Yep, all have an evolution with car makers that have similar styling across the board.............
So, why would it be any different these days?
Gov. fuel standards "these days" really does dictate aerodynamic cooky cutter cars. Everyone seems to like the earth tone colors too. The similar colors seem to add to the likeness.