I think it's commonly accepted here that if you don't have pressing loyalty issues like a neighbor Eleanor, dark age card bonuses completely outstrip most of the golden dedications. Excepting a few like CH/harbor players relying on free inquiry, or the monumentality civilian spam, things like +75% science with a HS or isolationism or twilight valor can be much more impactful early game than being able to pick up a couple extra builders and settlers.
I think the imbalance of how era score is distributed also creates the issue that successful empires that achieve golden ages after the mid game often find it hard to not chain them together. Virtually every source of era score is available the whole game long. If they had about half the era score locked to the current world era, so you had to be flexible on your goals, that would be another thing.
What's really funny is the power of dark age cards after the industrial is hilariously greater than the early game ones.
Robber Barons is so OP (+25%

in all cities with a factory and +50%

in all cities with a stock exchange, but -2 Amenities in all cities) I don't even understand how it's in the game. Collectivism stacked with it is truly egregious (Farms +1

, All cities +2 housing, +100% IZ adjacency, but -50%

great people points) like it can almost double your production, especially after the june patch for IZs. Just an aqueduct next to an IZ with these cards is worth 15

production (2 base, +200% w/ craftsmen& collectivism, x2 including the coal plant, plus +25% for the factory.)
Then we get to the new GS cards like Flower Power, which doubles the cost of non-rock band land units, but rock concerts give +100%

tourism, or Cyber Warfare, which gives you +10

against all info and future era units, at the measly cost of no grievance decay. Straight up +10 against all end game units is hilarious, especially since you can add in the fascism legacy.
Any late game empire that can leverage these is simply going to steamroll.
Can you imagine if early game dark cards were like that? +10

strength against all classical & medieval era units? Or renaissance Collectivism? The only thing chaining them down is that it's so hard to get late game dark ages if you are trying to win.