Before going to invest, you just need to inquiry that it has utility or not. In case, both have the potential and utility. I am not denying one rather than you can trust both. Both are established altcoins so far. I prefer both but if you ask me to pick one then I will pick Eth. Eth 2.0 is coming and everyone will see the changes soon shortly.
What kind of usefulness are you talking about, it is the BNB coin, I do not see any sense and usefulness of this coin at all.
I completely agree with the usefulness and great prospects of ETH, I also strongly believe in the coin at the moment and actively invest my money in it.