Yes, deflationary currency allows the rich to grow their wealth simply by saving in it. But also… an inflationary currency allows the rich to grow their wealth simply by borrowing in it and buying assets. Note: the poor can do both of these things too, though less easily.

The rich will… find a way. If wealth accumulation is a great evil then tax wealth, cap gains, and large loans against assets. Don’t demonize scarce things for being scarce.

Look at what bitcoin did, already in 2012!