because inflation will start and we need to fight it with high interest rates
What's the reality? Beats me!
If your $10 today is the value of $1 yesterday, it's very hard to store wealth in such a currency. So people move their assets to a less volatile currency.
Inflation guarantees that your salary is worth less when you spend it than when it was paid to you.
If inflation is high enough for you to worry about it, the solution would indeed be to convert it as quickly as possibly to something that is better at storing value.
At some point, people might start trading the thing that stores value really well and just retire that constantly depreciating currency.