It gets solved by inflating away the debt (debasement of the currency), it's the only viable way. You can already see they are heading in this direction in the suggestions that the fed inflation target should be raised to around 3%.

I strongly encourage you to look into the difference between Bitcoin and cryptocurrencies. Bitcoin has unique properties that ensure its decentralisation and strict monetary policy. Other cryptocurrencies are, as you say, merely copycats. https://nydig.com/learn/why-is-bitcoin-valuable

As mentioned above, central banks will not willingly adopt a Bitcoin standard. This is obvious. But as more and more individuals and companies adopt Bitcoin as their store of value, central banks and governments will be forced to acquiesce. They will attempt to make it difficult through regulations etc., however believing that they can stop bitcoin shows a lack of understanding about bitcoin. Bitcoin cannot be stopped. In fact it grows stronger every day as more and more people start building new Bitcoin focused software and services and more and more people adopt it.

The USD will likely exist as the global reserve currency for a long time, as other currencies hyperinflate, the USD will be the last fiat currency left standing. It too will eventually cease to exist in its current form. Bitcoin will become the global reserve asset as this is happening.

We are still very early and it shows, because most people still cannot see the difference between Bitcoin and cryptocurrency.