Currently, a lot of people are moving to the BSC and buying BNB, because of that, the BNB prices has pumped from $45 at the beginning of February to $120 in only few days. Also, BSC supports other coins like BTC or DOT, giving alternative uses to coin hodlers.
Also, Binance Bridge is a useful tool to change between networks quickly, easy and inexpensive. BNB is used to trade, pay fees, or invest in DeFi applications.