Of course not. There's no substitute for straight-up creativity and deep thinking.
But once you have your ingenious idea, you still have to design it, make sure it's clear to users, that they find it and can use it effectively. Your "ingenious idea" may turn out to be largely sabotaged if a button you thought had an intuitive label is misunderstood by 90% of users, or a link you thought was highly visible is being scrolled past by nearly everyone.
Yes, analytics is all about optimizing things to a local maximum. But you might not be anywhere near your local maximum. It's astonishingly easy for the first version of your ingenious idea to only be achieving 5% or 10% of the actual local maximum potential. We shouldn't downplay the difficulty or achievement involved in getting even close to a local maxima.
And you're correct that in user interviews, if you only ask what features they want, you're drastically limiting the value you might uncover. On the other hand, you'd better not ignore the features users are frequently requesting either. A lot of users are pretty smart and know exactly what they need, at least to get to that local maxima.