This is an interesting video. It takes both singers note by note first a clip of Grande then Jansen then back note by note. Jansen is a symphonic metal singer who also sings opera.
Jansen reaches each note effortlessly. Grande puts more effort into it.
But is it fair? Grande and really all pop sticks to the comfort zone with a rather narrow range. High notes are an audience treat not something sustained. Some singers were the exception Laura Brannigan, Whitney, Beyoncé, Celine, Mariah etc. But pop songs are essentially songs audience members and listeners can sing along with. Although the ones I listed are more power ballad singers who also does pop.