After you turn 65 there is no penalty for using your HSA for non-medical purchases, you just have to pay income tax on withdrawls. This effectively turns an HSA into an IRA after you turn 65. So you can contribute pre-tax, it grows tax-free, then you can withdraw without any penalty - making it effectively just another retirement account.

https://ourtaxpartner.com/hsa-distribution-rules-after-age-65-medicare-premiums/