Honestly, I tend to think they don't give you enough to truly differentiate a species. Precisely why I go with the ethics expanded that doubles your options and increases your points to 5, an increase to 10 trait picks maximum (no default trait point bonuses, but with repeatable tech to get more trait points. Makes bio-ascension worth something as a bonus) with additional traits mods, and double the amount of civics you can have at the start along with some new civics mods (would prefer five or even six, but you run out of room in civilization creation and I haven't found a mod to expand those menus). The collective bonuses and maluses of that increased amount of traits, ethics, and civics is enough to actually feel a difference in playstyle, while there really doesn't feel enough in the base game outside of a few specific civics.
Agreed there. So far I've played pacifist materialists, militarist materialists, inward perfectionist xenophobes, authoritarian pacifists and now life-seeded democratic pacifist materialists, and every play through except the life-seeded one felt remarkably similar. That one is mostly different because of the lack of colonization. The inward perfectionist empire
probably should have played differently from the others, but I rarely engage in diplomacy anyway, so it didn't.
The bonus percentages for most civics, traits and ethics don't produce a change you can
seriously feel in most cases. Playing as a spiritualist probably does feel pretty different from materialists though, with the robot ban and shroud mechanics, but I haven't tried that yet. Nor have I tried a machine empire or any flavor assimilator or exterminator, which I'm sure
do feel substantially different.
In any case, new dev diary today. We finally got to see what stability is, what amenities are for and how crime works. Having to provide amenities for your population makes them feel a tiny bit more alive, and I'm curious to see how different government types interact with the new crime system. Ultimately, it looks like it boils down to a more nuanced version of the old happiness system where different government types can choose to maintain stability in their own way, which is nice.