Legacy points also unlock leader attribute points

for example cultural legacy point unlocks a cultural attribute point.
Ok guys, I will try to explain it once again
"Must" is perhaps a bad word here. Let me put it this way: if you introduce a certain currency into the game there is a reason for this. You probably want to give some benefits for achieving this currency. Players are encouraged to grind it because it can be changed for some benefits. It makes a player stronger, and in general, is a reward for him. The more effective way a player grain this currency the better his reward.
This is how it works in every single game. So yes, perhaps you don't
need to collect this currency. You
want to do it. This is the reason this currency is in the game.
Legacy points are this kind of currency. And are very impactful because:
a) it's valid in all three eras.
b) unlocks a strong versatile and universal leader power:
https://well-of-souls.com/civ/civ7_overview.html#leader_attributes come on just look at those beauties.
c) buffing your power in the late game.
So yes. You want it because it is impactful and makes you stronger.
So what is the problem? You can archive one kind of attribute point: cultural, economic, militaristic, or scientific. So if you want to be strong in for example scientific game you want as many scientific attribute points as you can. So you adjust your strategy, and your choices to archive as many as you can. If you have a scientific game in the ancient era and in the next era civilization A that is good in a scientific game you will probably want to pick civilization A, over B or C. But you have only B or C to choose. This is not only limiting but makes ancient era civilization with a B or C option significantly worse than another scientific civilization with an option of picking A.
To get your prize you want to play a combination of three scientific civs. Not because you must, but because this is how the game is designed.
So do we have more options and Civilizations to play or less?
And you, as a player: Do you want more impactful and rewarding options in your game or less?
And this is how you can fix it. Either let us mix all civs to get our reward from legacy points, or make legacy points more flexible: Any archived legacy point should enable any leader attribute point, and any archived legacy point should speed up any late-game project. Or both.
Is this complicated? No. Is this hard to introduce? No. Does this turn upside down all the mechanics? No.
Can it be customizable for players? Yes. Does it give you more options and more flexibility? Yes.
So what is controversial here?