But there are plenty of people in the world more powerful than Lex Luthor. World leaders, politicians, fellow industrialists etc.
And in the few sequences we see him interacting with anyone with any kind of serious power in the film, what's he doing with them?
He is either displaying his power and messing with them, or gaining the upper hand over them somehow. This is a major part of this version of Lex Luthor.
You say he mistrusts metahumans, but then he goes on to create something far worse---like the equivalent of 5 Superman's with Doomsday so why would he create something even more powerful that could destroy everything when he hates a guy for his apparent reason of power?
No, HE says he mistrusts metahumans. That is quite possibly an act designed to get clearance to make a weapon to kill Superman, which Finch foils. Though I suspect it's both Luthor's personal thoughts wrapped in an attempt to manipulate.
Looking for a rational reason for a villain to do everything is pointless. Villains, by their very nature, are seriously flawed individuals. Part of their tragic flaw usually has to do with something irrational they think or do.
If his issue is "absolute power corrupts absolutely" then I can see him draw his hypothesis from Superman's f*** ups. But instead he creates those f*** ups to validate his hypothesis whilst Superman does absolutely nothing to support it. Which clearly shows that his hatred for the man is far more than just that if he has to create situations for him to look bad.
Superman's actions in Metropolis have been viewed as a serious threat/problem within this franchise, and by viewers of MAN OF STEEL. They are heavily referenced in this film.
That alone is enough for Luthor to be concerned, and for Bruce to be. If we accept that the arrival of a superhuman race capable of causing that kind of massive destruction and upsetting the balance of power in the world is concerning to Bruce and the rest of the world, then we have to accept the same for Luthor.
Just the sheer amount of effort he goes through in his convoluted plan makes you think Superman did something to him personally but he didn't...
That's the issue really. Zemo in Civil War has an equally convoluted plan but at least he has a dire personal hatred and vendetta to fulfill and thus, the effort is worth it. The Avengers came in and destroyed his family.
Superman has done absolutely NOTHING to Luthor.
Except that for people with serious ego issues, someone being more powerful than you can be a deathly serious, personal issue.
If you think about it, Superman has effectively "done something" to not just Luthor, but to the entire human race, simply by revealing himself to exist.
If anything he has helped Luthor by giving him contracts to rebuild the city---making him richer. So what does Lex hate here? If absolute power corrupts absolutely then why create situations to make him look bad? And is he not worried he'll get corrupted via the power? Why go to such lengths for some arbitrary thesis? What has Superman done to (without his intervention) to back up said thesis? Nothing.
Superman potentially threatens the very existence of human life and the existing power structures in the world. Batman and Luthor have similar issues with Luthor...they believe his power represents a shift in the balance of power away from humanity. And to be fair, if Superman wasn't a good person, it very much would.
The movie makes it readily apparent that Luthor has issues with power and control.
Within the film, when he cannot control someone, he destroys them (Senator Finch).
He cannot control Superman. Therefore he must destroy him.
If his problems are with metahumans in general. Then wtf would he create something far worse?
Because he can. Because it presents him with the means to destroy the thing he hates. It's not rational. It's not meant to be.
Other than some ill fashioned supposed ideological stance that is paper thin to begin with, and doesn't warrant any of the effort he goes through--this Luthor has no real reason to hate Superman.
I don't know about "real"...he has no "logical" reason to hate Superman. But as has already been pointed out, hatred often isn't logical. It is Luthor's illogical hatred and psychological need to control others that, in fact, makes him a villain.
To me it came off as, Superman and Batman needed to come into conflict so they had Lex be the guy to spark the flame and get them together by pulling various strings, but in the end there was no real reason for himto do so---other than some half baked philosophical stance thrown in the last minute to make it appear deep but instead was quite paper thin along with some abusive history with his father which is given one line and never really explored AT ALL.
To be fair, Luthor's reasons for hating Superman have never been particularly logical or deep.
Even the much-celebrated "you diminish us as a species" angle doesn't really hold much water in that regard, because Superman's presence does not, in fact, prevent the potential of human achievement in any real sense.
Nor has Lex Luthor traditionally, even in modern comics, been a particularly deep or hard to fathom character. He's a creature of ego with fairly simple drives that he masks under an illusion of complex ambitions. But it usually boils down to something fairly petty, usually his ego.