If we see thw growth of BNB now it is will making ETH move.
But ETH is keep strong and still good coin for now, maybe if BNB can overtake ETH it need a long time like 5 year or more.
Juat my speculation for this case.
it is because BNB is more growing in this year and makes people think If BNB will overtakes ETH, I think ETH is stronger than BNB and this is not a fight but this is who the best coins is are. everyone already knows that ETH is a good platform and a good coin, it takes a long time to be popular on crypto like Ethereum. of course BNB must try hard to be popular like Ethereum.