First I think that NEO just one of the projects that was announced like ethereum killer! If I remember correctly they said the same for tezos, stellar, tron and some other platforms, like some of them can close to eth!? For now they can only dream about it, and maybe with a lot of work some of them can come close to ethereum, but that is a big question.
Binance is doing a good job in last two years, it's a fact. They entered strong and they are active everywhere! But it's the same thing for bnb, they will have to do a lot more to get closer to ethereum.
So many projects out there have proclaimed themselves to be the true "Ethereum Killer". But at the end of day, they're unable to take down Ethereum's place on market. I think that Binance's "BNB" cryptocurrency will be no different. The company has announced the implementation of smart contracts into Binance Chain, but the Blockchain network is still far behind Ethereum in every way. It lacks mainstream adoption and an ample ecosystem of dApps & tokens. Not to mention, most developers are working on Ethereum nowadays. It'll be hard to "tackle" the leader of the smart contracts space after so many years of success.
The tried-and-tested smart contract platform (Ethereum) will always be #1 no matter what. Other alternatives like Tron and EOS may have better scalability than ETH, but they lack mainstream adoption. The Binance Chain promises faster and cheaper transactions than Ethereum, but it also lacks mainstream adoption. Besides that, BNB is much more centralized than Ethereum itself. Basically, any cryptocurrency which relies on DPoS or BFT consensus algorithms, are subject to centralization. Considering that Binance Chain is heavily centralized, it's unlikely it'll be able to "beat" Ethereum in the future. Comparing decentralization vs centralization is like comparing apples vs oranges. Both Binance Chain and Ethereum are completely different from one other. My guess is that they'll serve unique purposes in the mainstream world. Businesses and companies will find BNB attractive for their needs, while ETH will bring the attention of everyday people. It's not about which cryptocurrency is able to replace the other, but rather how useful Blockchain technology is worldwide. As long as BNB and ETH are useful, there should be nothing to worry about. Just my thoughts