Yes, you get back dollars valued in today’s current value.
If you invested in the stock market and did average - about 9% - you would net ~6% after losing purchasing power.
If you invested in stocks at a bad time, your return may be zero and you average a loss of -3% per year in purchasing power.
Totally bogus/flawed analysis.
Each company stock is constantly being adjusted to inflation. If they are a seller of services, they charge MORE DOLLARS for those services if the dollar inflates. If they are a seller of commodities, they sell their product for MORE DOLLARS if the dollar inflates. If they have real estate holdings, the price of that real estate is valued at MORE DOLLARS if the dollar inflates. All dollar inflation is in the current value of the stock so to say you lost X after losing purchasing power is flawed.