I personally would prefer Ethereum, because :
1. Ethereum is more experienced than BNB
2. more people trust to invest in Ethereum than BNB
3. Ethereum price increase is higher than BNB
4. more projects use Ethereum than BNB
5. Ethereum ranks 2nd on coinmarketcap while BNB ranks 4th on coinmarketcap
6. many people agree that Ethereum is the king of Altcoin
that's my reason why I prefer Ethereum rather than BNB at this time.
You've forgot to mention that Ethereum is decentralized, whereas BNB is utterly centralized. The latter blockchain sacrifices decentralization/censorship-resistance for convenience/ease-of-use. Most people don't care about decentralization these days, so they'll go with Binance Chain anytime. It's a pity considering that this defeats the whole purpose of crypto.
At least, decentralized cryptocurrencies won't be going anywhere. Ethereum will still be the "King of Altcoins" because no other blockchain can compete with it in terms of security and reliability (besides Bitcoin). This is the reason why most developers build their projects on Ethereum instead of Binance Chain. As long as this is the case, BNB will remain behind ETH in terms of market cap for a very long time. Just my thoughts

Maybe "utterly" centralized is a tiny little bit of an exaggeration as they do have 21 validators. What I don't know though is how the geolocation of those validators is distributed and whether they also frequently change or are fixed (for a fixed period of time?)? I haven't been reading enough about it to tell whether collusion between validators could ever be a serious threat or whether there are any counter measures in place. 21 is still a very very low number compared to a decentralized network like Ethereum, but it is at least not a one man show as it is with real centralization.