Question

why is equilibrium state attainable from either way

Answer 1

$\large{\bf{\pmb{\mathbb{\text{\red{Answer}}}}}}$

${\pmb{\mathbb{\text{\red{Equilibrium}}}}}$ state can be disturbed and reaction adjust its forward and reverse rate accordingly. ... ${\pmb{\mathbb{\text{\red{Equilibrium}}}}}$ is itself a state when rate of forward reaction become equal to reverse reaction so reaction does not stop.

$\bf{\pmb{\mathbb{\fbox{\red{Hope it's help you}}}}}$