i don't think its "hate". they're just too similar of egos to be able to be near each other for too long.. like two stars getting too close. they're inevitably going to collide.
and safe to say theres a bit of a rivalry there, probably beneath an authentic friendship. i dont think they were just brofessionals. i think they came to genuinely respect each other as friends. but still, friends have disagreements.. betrayals to some degree or another. theres falling outs and theres just temporary funks. where you sort of resent each other and arent really talking, but in time you'll both get over it and be fine.
i think they both have certain strengths and weaknesses, which are probably linked and part of the same thing. and so with them, all you gotta do to hurt them is hurt their business. hit them in the wallet and they cry like you kicked them in the balls. they love their wallets. they love how much they're supposedly worth.. its part of their huge egos.
so needless to say its a sort of, "this town aint big enough for both of us" situations and Elon has no real leverage since Trump is the one holding office. Trump knows hes holding the cards even if Elon has more chips, and Don wasn't afraid to flex it on Elon after probably overstepping his boundaries.
Elon wants to only win, and Trump probably promised him that. but Trump has made and lost money so many times that hes not as attached or "invested" into his wealth in the same way. being president is different than simply being supremely rich. my point being, Trump is willing to make moves that are ultimately detrimental for Elon and America at large, as long as it serves as a catalyst for the kinds of changes he wants to see later on down the line. Elon doesn't want to suffer all the bumps in the road, but Trump is willing to let it rip and take us on a wild ride as long as it gets us where hes trying to go. as for the rest of us we gotta hang on behind and pray.