I guess the Binance WBTC is the most popular because of the fame of the exchange and many as often missed it as actual bitcoin there
When withdrawing Bitcoin, they present a list of 5 options
*, 4 of those are designed to make people accept fake Bitcoins. I wouldn't call it "popular".
*I haven't used it in a while, so it might even be more now.
They currently offer two different networks for withdrawal aside the main Bitcoin Network now...