Really? Let me explain.
The west learned another method of making steel, and this method was less labor intensive and more reliable, and so steel swords became cheaper.
Were these steel swords so cool that they were as great as damascus steel? I'll leave that to the afficianados to decide. What I do know is that western steel swords developed enough of the advantages of the damascus steel swords that the differences in performance were no longer significant. As often occurs in technology, good enough beat out excellent.