Serious question: who uses HSAs? Only folks with ongoing high cost medical needs?
Companies I've worked for will also match up to a $500 contribution, so it's free money.
On top of that, the HSA is a triple tax advantaged account (even better than a Roth IRA), so you contributions are tax-free (lowers your taxable income today), the growth is tax-free (no capital gains), and withdrawals are tax-free (for medical expenses). You can invest the money in the HSA in index funds and such. As an investment account, it's as good as you can get.
If you're healthy young person who has enough cash to pay up to the deductible amount (mine is $2500 but depends on your plan) for unforeeseen medical expenses, and have a company match, you should at least contribute to a HSA up to the match amount. It's free money. And hold on to it until retirement. You also don't lose the HSA value when you switch or lose jobs.
Also if you do need to withdraw from the HSA for health expenses, you can. Although if you can afford the expenses, just hold on the medical receipts and leave the money in the HSA to grow. If you do need to do a large withdrawal, gather up your medical receipts and you can withdraw up to that amount with no penalty.
At Google the HSA is cheapest for almost everyone, whether you are a single person with almost no health expenses or a family with high expenses.