> How much do you trust your government with your money?
I cannot fathom the reasoning that would lead you to believe this question is a big gotcha.
The value of any currency comes from the trust in the economy and military of the governments that stand behind it. The USD's value is backed by the economy and military of the United States. The Euro's value is backed by the economy and military of the Eurozone countries. If you live in the US and the economy collapses to the point the USD loses its value, the value of the USD will be your least concern - same if the US were invaded by a hostile military force and unable to defend itself.
Your currency is literally backed by your country. Your country issues the currency and your country sets the rules for how much additional currency banks can conjure into existence. Whether you use that currency in cash, bank transactions or payment systems doesn't affect that point. Cash is the only one of the three that's meaningfully different in that it allows the physical transfer of money without a "paper trail" because you can exchange it for goods and services directly (which doesn't apply to e.g. handing over keys to crypto wallets as part of a transaction because you can't move the balance off the wallet without leaving a digital trail).
There is no inherent value in cryptocurrencies just as there is no inherent value in state-backed currencies. The value of cryptocurrencies primarily hinges on their use as a speculative investment - even stocks or futures have a more concrete value basis (representing ownership of parts of a company and future ownership of trade goods respectively). This means its value is not tied to the performance or power of any one state but it also makes the value much more volatile and unreliable and much easier to manipulate.
Cryptocurrencies also stil rely on trust: for most cryptocurrencies you have to trust the people who issued it (and in some cases the underlying code), given how many have suffered from "rug pulls" and pump-and-dump schemes before. For currencies like BTC you also have to trust that no single actor can be able to perform a 51% attack. For currencies like ETH, you have to trust the smart contracts that might be involved (and have been exploited/abused before). Most people also rely on third party services to actually trade crypto currencies, so they need to trust those as well and there have been plenty of scams involving them even where they didn't turn out to be unreliable outright.
All currency is vulnerable to manipulation by agents with control over disproportionate amounts of it - billionaires, megacorps, banks, states using it as a reserve currency, etc. But non-cypto currencies suppress some of that control with their own and they have a symbiotic relationship with their currencies (i.e. if the USD does badly, that affects the US economy, which affects the US government budget, which affects its ability to maintain its institutitions including the military).
So the question then is not how much do you trust your government but do you trust your government more than the wealthiest other actors (domestic and foreign) that would exercise influence over the currency in its absence. Given that the state is not only the only thing enforcing the idea of property rights but also able to take everything away (including your physical freedom and life) from anyone who lives in its sphere of direct influence, even if you distrust your government more it's a moot point unless you also have the ability to flee it at a moment's notice if necessary - and I'd wager that's not the case for the overwhelming majority of people.
You say we may end up with systems like Pix for each country/union - sure but there's no reason there can't be interoperability between them the way there is with SWIFT transactions. At the moment Brazil seems to offer Pix International and Pix Roaming to open the system up to tourists and Brazilians travelling abroad but there's no reason similar systems can't develop a standard for direct compatibility without having to require support by each foreign bank or POS system.