This is a very interesting question and I have been thinking a lot about what that may look like.
It seems to be a brute waste of resources to have 10 - 20 large liquidity pools for BTC - USD. They should share this liquidity, while builders should be incentivised to participate and compete on fair turns.
Not many know that among various standards, the ICP is building out ISO 20022 Compliancy, this new standard is the new financial standard for transfers of value, such as money, debt, equity, derivatives, forex etc. Basically, this opens up ICP for a quadrillion-dollar yearly market for payment messages and financial settlement.
Dfinity Forum ISO 20022 discussions and links to github:
The ISO 20022 standard is important because it enables all corporates, all banks, central banks, payment providers, and governments, even stuff like robots, to pay (AND SETTLE!!!) lightning fast even though they may use various types of currencies.
Bitcoin has a great store of value (but needs scaling as ICP provides, liquidity and smart functionality)
XRP Foundation and Ripple are working on liquidity, their thesis is that liquidity begets liquidity and there would be one hub/liquidity pool that is dominant, this is relevant for the reason that the world is becoming multi-polar and coalitions or regions such as BRICS wants more independency from trading everything against USD. One notable aspect of XRPL is a slow roll-out, they invented DEX and they invented Smart Contracts, for example, both Justin Sun and Vitalik Buterin were involved early in Ripple. XRPL is I believe trying to position itself as the backbone for payments and settlement in the global ecosystem, and they are not likely to spit out technology at keep up with the innovation at a level of ICP.
EVM (Ethereum) seems to have be championed by banks, currently, it is the standard for blockchains (Defi) and for example, JPM uses this type of environment for ever-increasing volumes of payments.
ICP role in such systems can be the underlying infrastructure, such as decentralized hosting / true (corporate) DEFI. Front End and giving interoperability connecting various crypto tech.
Bitcoin which does not follow the ISO 20022 standard, and likely would struggle to have this built out can still benefit from global payments, scaling on top of other solutions. Putting Bitcoin on a level playing field with the USD, Gold, Mastercard, etc
(Pay with anything, receive anything, anytime, at lower cost, faster, without locking up trillions as collateral)
It does seem intuitive to me that ICP may be one of the missing pieces of the puzzle, complementing all these other various systems.
But I suppose there is 1000 different ways to facilitate - adding blockchains on top of ICP infrastructure is (I think) a large advantage. And if someone then wants to use Ethereum Virtual Machines and liquidity from the XRPL, that is one way to go about things. Basically, Elon Musk should be definitely be looking at ICP for whatever he is trying to accomplish.
In the future, I imagine you can do peer-to-peer blockchain transactions - currency agnostic. This may be possible with online identities such as the Internet Identity.
Lower-hanging fruit is probably facilitating banks, and payment providers to build on your infrastructure, because these safeguards the end users - corporates and grandma’s bank accounts, and they are not gonna give up their immense power, liquidity and customer base without a fight, which is possible under current regulatory landscape.
(The banks are currently cannibalizing each other, let’s not intervene nor give them a common enemy to unite against).
Instead of creating a dex as a core technology, perhaps ?? developers can explore also solutions such as “sharing liquidity on a core protocol level” which gives advantages to everyone in the world who is looking to build dexes, and, engines for routing orders the cheapest route. (Not sure how things are built, maybe these solutions are already built)