I don't understand why BJs are considered non-negotiable in heterosexual relationships

It seems BJs are considered a non-negotiable part of relationships for most men. It doesnt make sense to me because PiV is already a male-centred sexual activity - they come from it almost 100% of the time, so what's the need of this additional "service"?? While vast majority of women dont come from PiV alone and yet cunnilingus - a female-centered sexual activity- isn't considered that important. I recently learned abt smth called "oral sex gap" - statistically BJs are more common than cunnilingus in heterosexual relationships.

It makes no sense to me at all because logically cunnilingus should be a more common practice than BJs - receiving cunnilinus without giving BJ should be more acceptable but in reality it's the reverse i.e, more women in heterosexual relationships give oral than receive it.

Not to mention, physically BJs are more harmful than cunnilingus- risk of gagging, choking,throat cancers (males have higher rates of being HPV carriers than females).I can't wrap my head around this disparity.