Well the usa are a coalition of states. Before the secession war, it was considered "a union of states" whereas now, it's seen as "a united state" (read that somewhere).
That's where the electoral college comes from, their federal state wasn't meant to be so strong at first, each state was supposed to keep more sovereignty that it has now (it still has lots of sovereignty now, maybe even more than europe when it comes to legislation fe?).

Also, we indeed don't elect a president of europe, and that might be one of the problems of europe. It kind of lacks democracy on some points (there are way too much commissions deciding for everybody, made out of people that are chosen by people that were elected, so prob not really close from what people want).

I stand my point; both systems are by far not perfect. If you think that a democratic vote by majority, even with two turns is a good idea, I invite you to check what happened in France in 2002 and 2017, those were not results that represented the leader wanted by the people.

I invite you to check what kind of election the borda count proposes. It's real interesting how our elections outcome may change.

Well, it is complex because europe actually isn't just one population (just like the us are different, but I think they are less than we are).
That's always the problem when you try to take a decision globally but let the individuals deal with the consequences individually.
It's unfair to give one vote per inhabitant because tiny countries such as luxembourg, etc would be heavilty disadvantaged. What if the common majority voters base (so Germany, France and the UK) decides that all fiscal assets should be normalized? Luxembourg will be against but will have to implement it anyway, and will suffer the consequences (loss of money). Basically, this means GFUk will dictate what happens in luxembourg, which won't be appreciated.
On the other hand, you can't give each country an equal vote either as it would be a denial of democracy.
That's why we have our deputies system and the us the electoral college systems. They get close to a direct democracy (trump won by ec, but lost on dd, but only by a few percent, he didn't "lost" on dd by 20-80% for example), while on the same time respecting the differences of interests of between different states. Nebraska people and Kansas people have different interests than californian people.

And tbh, the west and east coast may have an disadvantage considering the "power" of their vote, but they'll represent most of the votes anyway, so they shouldn't *** so much about it.

And as a final "shots are fired", there's not much good coming out of california those last years, socially and politically (go check the evergreen university incident). You don't want those people to decide what happens in your country (or in any country, actually).