This is one of those questions that does not have any pat answers. It may not even have any correct answers (as in, the future is something completely different)
Is the future of cryptos like what bitcoin maximalists think?
Right now, we have such a bitcoin dominance, that bitcoin could become the default world currency. But what does that even mean?
Could their be a future where we have bitcoin, and a few other coins that serve functions other than money? So, in other words, when talking about crypto-money, there is only bitcoin.
With the lightning network, and all the people building apps on top of it, this does seem like a real possibility.
Does the best ONE win?
One of the biggest questions is, is there really going to be one winner?
In the times up until now, there is usually one dominant currency. One rises to the top, and the others fall way behind.
This is easy to see with the Dollar and the Peso. If you have ever taken your dollars to a foreign country, you will often pay in dollars, and get change in pesos.
But, is this as easy to see in Europe? Do you pay in dollars and get change in Euros? Or do the dollars get rejected, and you need to change them to Euros first? My guess is it depends on how touristy the place is.
We can see how one currency can rise to the top, but we have never had cryptos, where atomic-swaps are a thing. So, we really do not know.
Will their be one winner?
Will their be many winners?
Will their be some kind of network effect, that makes everything look like one coin, but it really is a bunch of interlocking eco-systems?
What can bitcoin be used for?
Bitcoin's price is going to go to…
A whole lot of money!
The problem is, we tend to price bitcoin in dollars, but what if the dollar hyperinflates? Then it becomes really difficult to continue this old process. (How many 10 trillion dollar Zimbabwe notes per bitcoin?)
Bitcoin's price will go to a level where nations can settle trade balances with. Where multi-national corporations can settle huge payments with suppliers and manufacturers.
Bitcoin will be HUGE!
One satoshi will not be worth a penny, it will quickly pass that mark.
One satoshi may hover around a dollar for a while, but that will go away too.
In the future, i am betting that your mother & father, your siblings, your extended family, the community, will throw a party for when the young-ins get their first full satoshi.
In other words, bitcoin might be the big crypto, but most of us will never see a bitcoin, or really be able to use the bitcoin network. But, our world may be priced in bitcoin.
What the full bitcoin ecosystem may look like:
Lets say that only mulit-national corporations and countries can actually transact on the bitcoin block-chain.
What do the rest of the people do?
Lightning network is fine, but only really if you can commit it to the chain every once in a while. And if the price of goods are in micro-sats and pico-sats, you will almost never have enough to pay the price of an on block chain transaction.
And what about normal business? They need to pay their suppliers, shippers and manufacturers. And these (probably) need to be on a chain. Thus enters the possibility that other cryptos remain, are used and viable.
Just like we used gold AND silver (and copper and lead and nickel) there may be bitcoin and litecoin (and BCH or BSV).
Small businesses could afford the fees on the litecoin network, and so that is what they will use. And lightning network providers may back up to the litecoin network. So, all of this is priced in bitcoin, but none of it every really touches bitcoin.
And as lightning network evolves, i bet atomic swaps will evolve, and what we will be left with is a payment system that works on all levels, from the biggest corporations to the child wanting to buy a candy.
The intricacy and the interconnectedness will probably astound us today, but this is code we are talking about, and it is always evolving.
So, the question today, are bitcoin maximalists correct? Is not easy to answer.
In one sense, it may all be "bitcoin"
In another, it will be the best chains that provide the best service at a given level.
I can easily see a bitcoin-litecoin-doge network. Where they equate to todays $100 bill, $1 bill and 1¢ penny.
The only thing i can say for sure is that the lines in between today's block-chains will become very blurry in the future.
And there is a real possibility that the entire mess is just called "bitcoin"