And how those things not only survive but flourish in the same environment. It's mind boggling that those designs can co-exist without immediate repercussions! The complexity through the times amazes me!

I like to think about that too. Like I notice that there's a groove in the latch for a bathroom stall; an engineer decided to put that there, but for what reason?

Sort of. So much is the result of tiny incremental design improvements over decades or centuries. I remember the first time I took apart a small engine it seemed to work so well together that it was almost organic. Like it had evolved, which in a way it had