You are quite correct that many bad economic issues have developed due to the implementation of mainstream economics in the last 100 years.
However.
What you do not know, and cannot know, is what would have happened had Austrian economic principles been used for the same period of time.
Possibly we would have had peace and regular growth without inflation, deflation, depressions, etc.
Or quite possibly the world’s economy would have stagnated or gone into reverse and it would have 1/2 or 1/10 of the wealth it does now. Not to mention outbreak of wars as nations decide its easier to loot their neighbors than generate their own wealth.
You are comparing known problems with the present system to a theoretical system that has never had to bear the burden of implementation, and thus can pretend it has no problems of its own.
Except Austrian theory doesn't eliminate these, on the contrary, the Mises-Hayek Business Model Theory states that inflation, deflation, recessions, depressions, etc are all necessary parts of the economic cycle as balancing events.