That argument isn't true. Deflationary currency can destabilize governments, not the economy. Econonomies fail because they're run by incompetent governments, who spend more than they can afford.
Bitcoin is not guaranteed to be deflationary. It's deflationary when the economy is growing. It's inflationary when the economy is shrinking. Deflation will slow down economy, and inflation will accelerate economy. It's a stable self-correcting system, which would correct itself to match the average economic growth globally.
Bitcoin is not guaranteed to be deflationary. It's deflationary when the economy is growing. It's inflationary when the economy is shrinking. Deflation will slow down economy, and inflation will accelerate economy. It's a stable self-correcting system, which would correct itself to match the average economic growth globally.