Yes BNB is "only" a utility token and does not give any other benefits over the ones that you already mentioned.
KuCoin for example pays you a small part of their fees every day depending on how many KuCoin Token you own as a bonus passive income.
BNB still represents the biggest exchange in the crypto space though and with the burn that occurs every quarter BNB coins also become more and more rare.
You may be right, but this is a blockchain like Ethereum, where the same tokens exist and the commission is small. This is a good alternative to Ethereum, which is why it grows.