The situation is not that inflation makes your savings less valuable, it is that your non-dollar assets become nominally more valuable partly due to inflation, and that nominal-only gain is taxed.
Say you bought a famous painting for $10 million in 1990 money, and sold it for $20 million in 2020 money. The IRS sees (and taxes) a gain of $10 million, but actually your painting didn’t gain at all: dollars just became less valuable.
Most wealth doesn’t get held as money. Inflation in dollars won’t make your stocks, real estate or expensive artwork less valuable.
The situation is not that inflation makes your savings less valuable, it is that your non-dollar assets become nominally more valuable partly due to inflation, and that nominal-only gain is taxed.
Say you bought a famous painting for $10 million in 1990 money, and sold it for $20 million in 2020 money. The IRS sees (and taxes) a gain of $10 million, but actually your painting didn’t gain at all: dollars just became less valuable.