I have to say, this is a great question!
To answer it, first, we would have to think what are Bitcoin's real competitors for the first place, from a market cap standpoint. Looking at coinmarketcap.com right now, you have Bitcoin first with a market cap of 115B; Ethereum with 24B, on the second place, and Ripple on third with 22B.
For Ethereum to reach the first place, it would need an increase of 5X right now, while Bitcoin would have to remain at the same value. Considering that the market moves in trends, that is highly unlikely right now. When BTC is dropping, the alts are dropping, and, the market is rising significantly, only when BTC gets some gains, that is the trend right now, and it is unlikely to change until we get new highs.
Bitcoin is first right now because most people get into crypto through Bitcoin both because it's the most popular coin but, also because it's the most available on fiat exchanges. Besides being a store of value, Bitcoin doesn't have much utility right now, and it only holds the advantage because it's the first and most popular token.
Thus, there is a big chance that a certain flippening will occur in the future. But, what token will take the first place?
As of right now, Ethereum's main advantage is the fact that it is being used in ICOs but, the demand for ICOs has dropped significantly as we were all able to notice it this bear market; thus, the price of ETH dropped as well. The ICO hype is long forgotten, and, in the future, fewer coins will get created since the market is already saturated; thus, Ethereum will be affected by it.
Next, Ripple is highly centralized, and its price is manipulated because a big chunk of the tokens are pre-mined and held by the company. Its use-case is inexistent right now, and it has no chance to reach the first place in the near future.
As a conclusion, a flippening might happen in the future, it is very likely that it will, and we have no idea what coin will take Bitcoin's place but, it will probably be something that we don't even expect. It is improbable that such an event will occur within the next 12 months.
Thank you, and I hope that my answer was of help.
I personally think that EOS has a lot of potential. The numbers it is putting up on transactions per second is crazy.
If they can get the bugs worked out and start releasing some everyday use dapps it is going to be a game changer.
Also, this may seem a little biased, but even though it sits lower in the rankings, I think STEEM is going to move within the next couple of years.
STEEM is a great example of bringing the blockchian to the masses in a format that they can understand and relate to. It is impressive how much it has grown just over the past 8 months.
I do not believe that Bitcoin will lose its position as the #1 market cap coin for a long time. Why? It is widely thought that the next bull run will be fueled by institutional investors entering the space. They need to have custodial solutions and regulatory frameworks in place before they can even think of buying into any coin. Bitcoin is the oldest and the stablest in terms of market cap and other metrics of all cryptocurrencies. Institutional investors are conservative and they will most certainly buy into Bitcoin first as they have done this far.
Should Bitcoin lose its position as #1, I think the only two coins in a position to take the lead are Ethereum or Ripple. In the case of Ethereum, it will depend on scaling solutions being created and accepted by the community and in case of Ripple it will depend on how successful Ripple is at forming partnerships with major financial corporations.
I don't think that will happen this year but within ten years I can imagine an alternative such as ethereum will be worth more than bitcoin.