The Base game traditional view expanded: base feats that you feel needs a comeback!

[Lazy sweeper]

It seems to me Initially Civilization was only adding feat. But since Call to Power, that had everything from the beginning, including space colonization...
the path taken has been that of not giving a 1/3 new content and 1/3 away, but only 1/3 away.
In my graphics I included in green what It seems what was generally being accepted as very good core features, being flushed away one by one...
whilst the RED entries, had been changed, reshaped, but it was generally accepted as NEW content.
Religion added a lot in Civ IV.
The Iceberg is incomplete, but I would like to grow it more with time.
It's more like two intercepting Pyramids in my mind. Civ IV was in the middle, or a the base of the upward Pyramid, and from then onward, the Pyramid has reversed...
There is always less and less that can be added or innovated, and every change, seems to have to be a drastical subtraction game for it to continue...
So I stopped at one point between Civ V and VII...

These are my perceived base game feats, please expand on this, add yours personal takes, and specify if it's a feat that substitute another, add or subtract. If it make a meaningful change to the gameplay etc.

 

[Lazy sweeper]

AI for example is not included in the list.
Was AI a feat?
I never thought Ai in terms of bas game feat... untill later... when Ai was so incompetent that it could not wage a war...
Initially, people would complain that Ai was too strong, and in response, we got even STRONGER Ai...

AI in Civ V with 1UPT city bombardment, and overpowered ranged units, even a barely OK AI would cripple a modest city siege attack, the math has changed completely.
Civ V built bombers and fighters, and like in Civ III and IV, if you didn't build FLAKS, your attacking army would get crippled to dust.
1UPT exacerbated this mechanics so Flaks now had to defend at least all adjacent units as well... because you could not stack them...
Civ VI removed Ai the ability to build overpowered ranged units alltogether and this was inherited by Civ VII...
Civ VI had no Flaks or SAM units, that was taken away, and with it, basically Air combat was declared dead.
If Ai was given back the ability to use Bombers, Human players would have no means of defending..

Overpowered ranged units and 1UPT is a terrible combo.
But it's not so easy to tell what has been added and what has been taken away if we are talking about AI in all its aspects.
In Civ III the ultimate Army had at least one Flak in its units.