eth and bnb are coins whose volume is quite high and investor interest is also very much on the coins.
considering both of them are in the top 100 coinmarketcap, certainly there are many investors who put their hopes in both. I am one of the eth coin holders.
If given a chance and enough investment money to provide choosing both are good as there's a huge communities who are backing both projects. Like what you have said, investors and traders mostly based their choices with volumes and with numbers of trades it's undeniable that both projects are really passing the criteria of good project to invest your money, you can choose long or short term as it can produce outcomes that you are aiming.