My best (stupid) guess is weapons. US gov has a ton of weapons. Already sells tons of weapons. Now the prices will always remain stable. Other countries would love to know that 30 million usd would always be able to buy an f15. Other countries declaring war will increase the value of the USD, as buying weapons from us government will decrease amount of money in circulation.
That’s what inflation is and why governments target a low but positive level of inflation with monetary policies. The fact that your dollar slowly loses value pushes you to reinvest it. Very few rich people are just sitting on piles of cash.
If they didn’t also aggressively suppress increases to minimum wage and tax recapture benefits, I might agree, but in the long run inflation does more to devalue labor than it does to mitigate hoarding.