HSAs are a trifecta super power account. Contributions are not subjected to tax. You can invest and grow tax free, and if you spend money on qualified expenses, it comes out tax free. The money rolls over and grows each year, unlike an FSA.

In retirement, if you happen to use the money for something other than medical expenses, you just have to pay taxes. With the way things cost today, I cannot imagine I will have a problem spending this appropriately in retirement.