Bitcoin is plain and pure currency. Devs are working on introducing smart contracts to bitcoin as well (I forgot what that was called
)
Ethereum and Neo,ADA,EOS,ICX etc. are for programmable money(Smart contracts) and decentralized applications.
Now even if BTC somehow doesnt become the world reserve currency one day, I truly believe that these smart contracts will definitely play a major role in day to day life. The use cases for these are endless, such as Golem which launched their mainnet, it is a decentralized super computer. Even things like monetizing Facebook likes becomes possible.
We probably haven't seen a lot of the mind blowing use cases of programmable money yet. But this is surely a game changer for the whole world. The current smart contract platforms are very competitive against each other, and honestly they each have their pros and cons. I would recommend looking into all of them and understanding what makes each one better and worse, and buying some of all of them.
That said, I think once BTC can do smart contracts, coupled with Lightning network we will see some really interesting things come out of it.