I think both are worth investing and I am holding both of them but both are different networks, BNB has attracted huge investment during the past one year and it will continue attracting new project as being best alternative of Ethereum with much lower cost. Ethereum 2.0 is going to be fully implemented in the next few months which hopefully will reduce transaction fee significantly.
Tomorrow the London hard fork will run and it's part of the Ethereum 2.0 implementation to be even better than the previous one although in the past Ethereum wasn't even worth calling it bad just because there are others that are cheaper so let's see together how it's implemented run.