Ethereum, being the world's second largest cryptocurrency by market cap, has all the potential of replacing Bitcoin in the future. It's more than just a cryptocurrency, being a platform for the development and execution of smart contracts (aka dApps). With ETH, it's possible to launch alternative cryptocurrencies without the need to start a Blockchain from scratch. It's also possible to use the ETH blockchain for other purposes such as voting, proof of identity, verification of documents, and more. In contrast, Bitcoin's only use is for finance where it cannot be implemented in other areas by its own.
Given all of the benefits Ethereum provides on top of Bitcoin, it makes me wonder whenever it'll be able to replace the pioneer cryptocurrency within the future? As long as, Ethereum keeps progressing in development and mainstream acceptance, it'll be much closer to Bitcoin every step of the way. What are your thoughts?

It could happen but for the time being, we should concentrate on Bitcoin, Bitcoin first then others will follow, when majority of the people in the world are now using Bitcoin, we can think of a better alternative, it could not be Ethereum right away, there's a lot of new coin coming or coins now that are now improving.