You pay taxes on the gains and what you put in when you take it out. Say you get 10% return with 9% inflation, You pay taxes on 10% gains even though your gains

You pay taxes on the gains and what you put in when you take it out. Say you get 10% return with 9% inflation, You pay taxes on 10% gains even though your gains were truly 1%. Also gains could be from any investments. If you have a Roth that you manage or is managed, your tax payment vs gains is worse as well.