How do you know ETH gas fees will be lower in near few months? I don't think it will happen soonTM, so I believe BNB's rise will go on in next couple of months. Even if they fix ETH gas fee problem it won't be near as BNB's low fees. People get tired over 100$ swaps so they switch out. ETH swap fees won't be 1$ anytime.
In October 2021 the Ethereum fees are around $49 million per day and for this about 1300 transactions were made. Ethereum transaction fee (Average transaction fee in USD) - Source:
https://bitinfocharts.com/de/comparison/ethereum-transactionfees.html#3yI have made trades on both chains in the last days and it is an extreme difference. I will only use bsc in the future when I have the choice.
A current comparison:
Binance Smart Chain Gas Tracker
Standard / 5 Gwei / (30-60 secs)
Fast / 5 Gwei / (10-30 secs)
Rapid / 5 Gwei / (5-10 secs)
Ethereum Gas Tracker
Können / 154 gwei | ~ 10 mins
Average / 155 gwei | ~ 3 mins
High / 155 gwei | ~ 3 mins