Certainly racism is most prevalent in the USA. The USA remains largely segregated by race. Whites, Blacks, Asians, Spanish-speakers, and Indians all have distinct cultures. Between that and the physical separation, there is (and always has been) a near-total absence of social interaction between people of these different groups...and this preserves a profound ignorance of each other, and a lack of empathy between them. Those conditions allow racism to continue and to flourish.
In contrast, families in every one of those segments either have a member (a son or daughter, a nephew or niece, a grandson or granddaughter) who is homosexual. The personal experience of knowing and caring for someone who is gay is not uncommon, and is not restricted to any one group. This is the opposite condition from the foregoing one regarding race. For that reason, homophobia is less profound or entrenched as racism in the USA, and it has become noticeably less pernicious over recent decades, as people become more open about their sexualities.