> Why do we need idols, though?
Because we're flesh and blood, i.e. utterly irrational.
> If there was no narrative, no idols, no celebrities, would people be less motivated to do science? Why do we need to lie to ourselves so?
Yes, definitely, a huge amount of what motivates scientists is desire for fame, being considered a genius, Nobel prizes, scientific immortality, and so on. It is entirely unrealistic to imagine that we can stop being like this, it's almost a religious belief, akin to thinking that, one day, people can live without sin.
> Personally I'm mostly uninterested in who did what, but maybe that's just me. It seems obvious to me that nearly every scientific discovery could have been done equally well by millions of people, it's just a matter of who had the resources to be educated, who decided to research the problem, who managed to snipe the answer first, and who had the right connections to get it acknowledged. They're still great achievements, for sure, but they're not the markers of exceptional genius we want to think they are, not for Turing or Einstein, but not for anyone at all, really.
This may be an accurate description of your personality, in which you're one in a million, or it may be that you're ignorant about the things that actually drive you. The vast majority of people are driven by some kind of desire for fame, recognition, status, upvotes, and so on.
Suggesting that Turing and Einstein were not "exceptional geniuses" is bizarre. Even in proper context, they were exceptional geniuses, just among other, lesser-known, exceptional geniuses. If we take your view seriously, we remove all human agency and uniqueness, we remove the idea of an "achievement" and we can only give credit to luck, the historical process, and various contingent circumstances. Even if your view is accurate, people simply cannot live that way. Creating narratives is part of what makes us human and narratives need protagonists (idols, heroes, whatever).