I can't really visualize how what you're proposing would work though. Can you give an example?
Consider the Inca. They were quite advanced, agriculturally, as I understand, and also in medical fields. What would their civilization have changed into if the New World had not been discovered and "polluted" by European thinking and ideas?
Why not a culture that doesn't discover internal combustion (perhaps they have no oil) and as a result advanced steam technology and pneumatics to "modern" levels, despite other areas of their technology still being at 18th century levels?
Why do we have situations such as Paper having a prereq of Civil Service.

There are dozens of similar situations in CIV.
There's got to be a certain amount of structure in a game, or else it all falls to pieces.
What's your basis for that conclusion?
And, who is to say what the "certain amount" is to be?
What use is it researching Bronze Working if someone else can get Iron straight off the bat? Also, where are the lines drawn? Surely someone can't start researching Fission from the get-go?
As I said, "unless there's some reason based in science".
Also we should be careful that we don't make assumptions. Why is IW "better" than BW? There are many applications where bronze or copper is a better choice than iron. And what if my civilization has Iron but not the metals to make Bronze? How would we "research" BW if we didn't have those metals
at all? Wouldn't we jump straight to IW?
What if there was some "metallurgy" or "metal working" technology which is a prereq for both? Then, you could choose whether you go for IW or BW based upon strategic game decisions, instead of being
forced to get BW before IW.
I think your idea might have some potential, but it seems very vague and ill-defined at the moment.
Well
of course. That's why the game designers make the big bucks. We could define it here, and certainly I would be glad to explore it. I have put thought into it but we should understand that a well-designed game requires thousands of man hours, just in the concepting (before you even get to coding).
Unless you can propose a workable alternative system, I don't see the problem with sticking (roughly) with what we've got: a semi-linear progression from the stone age to the modern age.
Because it limits replayability, it limits enjoyability, it limits player creativity and strategy. It also limits profit, because those things directly impact sales.