Knock-off Birkins, and allother Hermes prods, have been on the market for 5 + years.
Where there’s a demand...there’s a knock-off!
There's always cheap Chinese made knockoffs of boutique luxury goods. But they don't have the same cachet as the original. The original is hand-made from the highest quality materials and is designed to last a lifetime. For those who have exquisite taste and demand nothing but the best, only boutique will do. They can well afford it.
"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II Palelologus