Argument 1: Deflation helps everyone. The world isn't a zero sum game. If a miracle happens and we manage to use nuclear fusion (fusion, not fission) and everyone can enjoy pretty much free electricity, how are the rich hurting the poor? They aren't. In this case, the improved material well-being of the rich does not come from the abuse of the poor in any way.

Argument 2: If inflation helped the poor, Venezuela, Argentina and Turkey would be a paradise for common folk. It doesn't seem to be the case, does it?

About those comments on inflation.

Rich people have resources to store their wealth there where inflation can't take it (stocks, real state, getting close to the money printer). Rich people also have better access to credit, and remember: in the fiat world, the one who is better off is the one who can more easily and cheaply get in debt. It's the upside-down world.

On the other hand, poor people mostly have cash, because they are on tight cash flows and can't afford the friction and risks that comes with turning cash into other assets. If you only have a 100$ in your account, you won't be buying skyscrapers nor stocks with that.

Actually, you could argue that inflation is what keeps many poor people poor. I can tell you that the most hard-working guy in Niger is not going to get out of poverty any day soon as long as he lives under an extremely inflationary currency + capital controls + a complete disconnection from the traditional finance system. If he lived in a deflationary world, at least he could benefit of the cost of living decreases, regardless of his capital being small.