Why is the ages of consent 14, 15, 16 in Europe and 16, 17, 18 in America.
America is particularly schizophrenic about maintaining all social barriers between youths and adults (which is saying something, since the pedo hysteria is all over the world at this point), along with maintaining the illusion of youth asexuality as much as possible to satisfy adult power.
Also if an older man has sexual relationship with a girl in her late teens including 18 and 19 which are above the maximum legal age in the U.S. he could still be branded a pedophile and possibly ostracized although no legal action could be taken if she's over 18.
That is because like so many other terms right now, the word "pedophile" has been broadened to fit whatever the person wielding it against another wants it to mean, as accusing someone of that is the verbal equivalent of stabbing them in the gut with a sword. Hence, everyone wants to have such a sword in their metaphorical scabbard on hand whenever it may be required in a world where social media is so heavy with conflict and interpersonal hostility. It's especially useful to wield against your political opponents, of course, which is why conflicting ideologies so often accuse the opposing ideology of being "soft" on "pedophilia."
Finally, such a broad accusation is a useful tool in a media that so heavily favors virtue signaling and a love of punching "down" at the lowest hanging fruit. So many in America enjoy beating up on the weak while trying to come off as morally righteous at the same time. The "pedophile" accusation is thus one of the most important weapons in one's arsenal against people doing anything that others find "creepy" or offensive to their sensibilities, and high on that list right now are age disparate relationships even if the younger person is of legal age to consent. They know that calling Leonardo DiCaprio a "pedophile" for preferring to date women in their early 20's really hurts, and doing it from the safety of a social media forum like Twitter is a lot easier than walking up to the guy in person and trying to kick him in the balls.