One can argue that the Endless series got better system than most if not all of it's competition, and yet lacks something fundamental against most of them

Endless Space compared to Stellaris for one

UI - ES

Market - ES

Resource - ES

Ships - ES

Combat - ES (technically the same you throw your ships against each other numbers war, but ES is far easier to digest all in all, and far more involved with the cards

this involvement tho is a low bar)

Heros - ES

Planets - S (technically the same, difference is you see up front the planetary developments in Stellaris which is nice)

Events - S (same tune as the combat involvement, ES events outside of the faction might as well be a prolonged anomaly ping)

Governance - S (ES could have gotten this but S just have a better execution) S Governance is simpler, while ES felt undercooked like it could be more than it ended up as superficial

Galactic Governance - S (well we all know how the academy went, either turned off in the options or rescued with a mod) S had a standard system that worked

Factions - ES

Diplomacy - S (once again ES feels more but the execution didn't get there while S delivered with the standard formula)

ES 7 / S 5

ES wins then yes? no not really

as i've mentioned ES have better systems overall, but fails to deliver with the execution with the half of them and those failures leaves a bitter aftertaste

Stellaris may be simpler in a lot of ways but it delivered on this simple things and the parts it excels at blows the competition apart

S is far more chaotic than ES, as certain anomalies, events, or discovery may make or break a run, the most gamble i had running ES2 is by drilling a hole in my moon (what could happen right?)

being more unstable makes S runs more memorable, while ES is more "balanced" it is at its core devolves to numbers a game, more fidsi, CP, etc

the stability of ES hurts it for more than that, the discovery in ES is as bland as it gets because of it

we all know the resources, the anomalies, the "special" planets and nodes, even the factions

this makes a space game with the unknown, the exploration and discovery almost a non factor

there is no big secret or big scary or a big oh your scout just found a dormant Obliterator at like turn 6 what you wanna do about it?

poke it see what happens, try to take it home, leave it be it might agro you, leave it and let your friendly neighbor (Carver, Hissho, Riftborn, UE, Vody) get their hands on it what could go wrong eh?

there is nothing to fear but hostile factions having more numbers than you, that or a certain spear

Endless Space oddly enough feels like it have both too much and too little space

the lack of meaningful exploration and discovery makes it feel hallow

the rigid balance is like a noose, production of the necessary yield at certain points dictates the entire run

an Interesting take and assessment 

i like the design of Endless Space