I think that the crypto currency has already taken root in our world and its future potential has not yet been exhausted, and I think that now is just the beginning. Of course many will think that everything is complete and the crypt began to quietly fall from its place at the top. But you can also consider so that now there is a check on the nerves of people who invested in it.
There is an interesting expression "after falling to the bottom, there is only one way out, this is to climb the top
We are still in the early days of cryptocurrency and people thinking a market will cease to exist, most especially for a market that is already grounded, with a lot of support and development springing up every day, I feel it is absurd to have such a question of whether either of them will cease to exist in years to come.
Surely, we are all just here in the present and no one knows the future and we can only be optimistic and if we are to judge with the present, I want to believe we still have more room for growth.
OP is asking a question that sounds a little bit lame than it being a fact. No one knows the future, so asking us if bitcoin would cease to exist in couple of years to this time or if it will not is all B.S. The market is growing by the day, development is popping up daily and I see no reason why bitcoin would cease to exist and I do not see Ethereum ceasing to exist either, however, like I said, no one knows what the future holds. Just buy what you feel you want to take the risk of buying and live with it. As long as you understand the risk, then the rest is left for you to decide.