I would guess the reason they keep beating the Pope drum is they have some inclination he is class and we have a real dearth of batsman with impressive FC averages. He is one of the few that do. It hasn't worked so far, though. Him at 3 looks weird to me, he doesn't strike me as a 3.
To me it's a massive shame Butter hasn't really adapted to red ball cricket. In my mind he should be able to average 40 and be capable of game changing innings. There's no good reason he shouldn't be able to, he's got all the talent, all the shots. But I think sticking with Foakes is the right choice for now, he's averaging 28 - he needs to add at least another 7 to that but that isn't insurmountable and he's a good keeper.