  Hildebrand proved that the smooth approximation for the number $\Psi(x,y)$ of
$y$-friable integers not exceeding $x$ holds for $y>(\log x)^{2+\varepsilon}$
under the Riemann hypothesis and conjectured that it fails when $y\leqslant
(\log x)^{2-\varepsilon}$. This conjecture has been recently confirmed by
Gorodetsky by an intricate argument. We propose a short, straight-forward
proof.
