I agree that although the second layers provide discounted transaction fees, they are still higher then fees on Binance Smart Chain. So in that sense you are correct.
In fact, one of the second layer solutions may migrate to its own chain to lower those fees further.
The centralized nature of BSC allows them to better control fees charged by the 21 nodes providing blockchains ledger integrity. It’s hard for a decentralized network like Ethereum to compete.
POS on ETH 2.0 should, as you point out, solve transaction speed and capacity issues, but it’s still unclear what the fees are going to look like on that new network, so I agree that we don’t know how much lower the fees will be.
I am waiting to see if the large developer braintrust at Ethereum can solve this through further innovation.