While BNB generally follows the BTC trend (sometimes with a short delay) in its price movement, it's worth noting that this coin is also valuable as a source of Gas for the Binance Smart Chain.

If you're trading on Binance there are several advantages to holding BNB like fee discounts an option to participate in Binance Launchpad (i.e. free tokens for staking).

But putside of Binance and the BSC ecosystem I'd say investing in BNB is not much better than investing in Bitcoin.