I wonder if there is any reason why some affinity help to get their stars whereas some other don't help.

If we list affinity that allow action to get your associated Era Star :

- Builder : Land Raiser, allow them to change the output of a city to build new district faster + Passiv reduce the stability cost of new district

- Expansionist : Under One Banner, allow them to capture new territory without war

- Agrarian : Land of Plenty, allow them to steal population from neighborhood. (I'm pretty sure this population count toward their stars, but maybe I forget it)

- Scientist : Collective Minds, allow them to change the output of a city to research faster

- Diplomat : Dematerialization, generate leverage point on in a territory + Passiv all unit can collect leverage point on the map

Whereas 

- Aesthete : Cultural Blitz, allow to collect a massive amount of Influence but it didn't count toward era stars

- Merchant : Power Investor, allow to collect golds but it didn't count either towards era stars

- Militarist : Iron Reserves, is not really useful to get military stars (unless someone think the opposite)

I know Vigilance (Militarist) and Mediation (Merchant) passiv can help a little toward their stars, but I'm not sure they're as good at getting their stars.

For Aesthete and Merchant, is there any reason why their action don't help to their stars ?

Regards,
Elphy

I'd rather the merchant and aesthete help as well, especially since merchant and aesthete stars are among the most challenging stars to collect. If the numbers for them have to be adjusted to account for that, I'd prefer that, just because it would feel a little more active from a player's perspective.

The militarist ability is really powerful! You can insta-build an army, and now that you can upgrade from the somewhat niche reserves, it's even better. So I'd definitely say it helps you win a fight.

Arachnodork wrote:
I'd rather the merchant and aesthete help as well, especially since merchant and aesthete stars are among the most challenging stars to collect. If the numbers for them have to be adjusted to account for that, I'd prefer that, just because it would feel a little more active from a player's perspective.

I'm concerned that making those values count — and increasing the star costs to match — would make those stars even harder to achieve for non-Merchant, non-Aesthete cultures.

I find Aesthete and Merchant stars can be hard to come by unless you've been one of those cultures at least once.  Once you've got some money- or influence-generating districts or LTs in place, I usually do alright by those.  It's like how early game science can be really low unless you purposefully invest in it.  We passively make population and districts and territories over the course of the game... once you purposefully invest in money and influence a bit, those stars become quite attainable.

Arachnodork wrote:
The militarist ability is really powerful! You can insta-build an army, and now that you can upgrade from the somewhat niche reserves, it's even better. So I'd definitely say it helps you win a fight.

Agreed, this is really nice!  A few days ago, in a weekly multiplayer game I'm in, I advanced from the Edo Japanese (emblematic halberdiers) to the Ethiopians (militarist), which let me instantly raise an army of seven recruits from one of my cities and upgrade them all into a stellar unit.

I'm pretty sure people tend to under-prioritize influence and money and find therefore those harder to get.
Military stars can be quite tough to generate in a peaceful environment (not even mentionning diplo ones...)