Jamaica has influenced hip-hop through toasting/sound systems/sound clashes. So to act like Kool Herc or Jamaica didn't have any influence on it is a farce
One of the first rappers at the beginning of the hip hop period, at the end of the 1970s, was also hip hop's first DJ, DJ Kool Herc. Herc, a Jamaican immigrant, started delivering simple raps at his parties, which some claim were inspired by the Jamaican tradition of toasting.[41] However, Kool Herc himself denies this link (in the 1984 book Hip Hop), saying, "Jamaican toasting? Naw, naw. No connection there. I couldn't play reggae in the Bronx. People wouldn't accept it. The inspiration for rap is James Brown and the album Hustler's Convention.".[42] Herc also suggests he was too young while in Jamaica to get into sound system parties: "I couldn’t get in. Couldn’t get in. I was ten, eleven years old,"[43] and that while in Jamaica, he was listening to James Brown: "I was listening to American music in Jamaica and my favorite artist was James Brown. That's who inspired me. A lot of the records I played were by James Brown."[41]
However, in terms of what we identify today as "rap" the source actually came from Manhattan. Pete DJ Jones said the first person he heard rap in “Hip Hop style” was DJ Hollywood a Harlem (not Bronx) native[44] who was the house DJ at the Apollo theater. Kurtis Blow also says the first person he heard rhyme in Hip Hop style was DJ Hollywood.[45] Hollywood stated that he like the way Frankie Crocker would ride a track, but he wasn’t syncopated to the track though. I liked [WWRL DJ] Hank Spann too, but he wasn’t on the one. Guys back then weren’t concerned with being musical. I wanted to flow with the record.” And in 1975, he ushered in what became known as the Hip Hop style by rhyming syncopated to the beat of an existing record uninterruptedly for nearly a minute.