I have a pretty strong dislike for opera, but I am aware that most opera singers can blow away most pop/rock singers in every technical way that can be measured.
today that's not so true. after the 60's, the quality of technique decreased a lot, most singers can't articulate the words making it impossible to understand what they are singing, and also they last few years due to extended abuse of the vocal cords.
in fact, after Pavarotti, opera singers lost their "fame". he was from a previous age, lasted until his death.
another thing is that opera is written in the range of the singer, so a tenor won't ever sing a baritone piece, and never go out of his range.
in pop/rock music most songs are written "for the instruments", and the singer has to adapt. the key of most ACDC songs is so wrong for a man, and that's why both Bon Scott and Brian Johnson have to sing so high in a screamy/squeaky voice, but they are written to sound good on guitars
when we talk about pop and rock singers, that's where we encounter "humanity" and feelings; from the late 60's up to today many singers were just good frontmen.
one example is Jon Bon Jovi: he's the lead singer, he has the character, but Richie Sambora is a better singer, with better intonation and technique, and that's why he sings all the backing vocals even in ranges extremely difficult for a tenor.
however he's not the frontman, because he can't sing with the same attitude.