(Hyper)inflation

I learned a lot reading about Bitcoin and gold, but i was wondering if there is a guarantee that the US Dollar will collapse in value? If not, what prevents it from not going down? I know it is the reserve currency of the world but printing more USD doesn't automatically mean there will be high numbers of inflation (or perhaps hyperinflation)?

What is the difference in regards to the recent tragic events in Turkey, Libanon, Argentine, Venezuela, etc.? Is it all because of money printing that these currencies lost all of their purchasing power? It looks as if other countries will follow?

I find this very interesting but I still can't see the full big picture. Any good sources to keep learning about all this?

Do you guys believe the Euro and Dollar one day will completely dissapear? If they go to a digital Euro/Dollar .. How will that be different from the cash we are using right now?

Do you think the Euro will get the same faith as the USD? I keep reading about money printing in the USA but I hardly read anything about Europe (I live in Europe btw).

I invested a lot of my money into Bitcoin. It's actually the only asset I currently bought as an investment. I am thinking about buying stocks (particularly index funds) since every money book I read recommends this and i also want to diversify a little for if BTC would fail. Now I'm wondering in which index fund I should invest .. I particularly wonder if America will remain the most powerful capitalist country or if China will take over in the next 50 years .. That's the only thing preventing me from investing in stocks. I don't know what to invest in and especially since now all stocks are so high priced ..

I know this is kind of a ramble but I would love to gain new perspectives from everybody. Thanks for all the insights!