At worst (e.g. if you never have any health-care related expenses) it just acts like a IRA, still garnering you tax-advantaged savings.
At worst it is an IRA that missed the payroll taxes (which is great), but there is no 72(t) and you have to wait until 65 to start pulling from it. On balance, I'm having a hard time getting excited about it.
You're 34, so if you continue to contribute the $6900 HSA family max (ignoring the after 50 catch up) until you're medicare eligible at 65, and you get a 5% after inflation return you'll end up with $488,249.45 in today's dollars in your HSA, so that's the most you could possibly end up with. If you retire sooner, presumably you'll stop contributing unless you find that it would be tax advantageous to withdraw from IRA and move that money to HSA, or you find yourself making unexpected income that you want to tax shelter.
How does that $500k compare to an amount you would be comfortable retiring with? If it's close you might be right, but as long as your FIRE amount is significantly larger than that then there's no reason you can't withdraw at a higher withdrawal rate from other accounts and withdraw from the HSA once you hit 65.
If you think about it another way, there's a 20% early withdrawal penalty on non-healthcare HSA withdrawals, which is 10% worse than the early withdrawal penalty of IRAs, but once you figure in the 7.65% FICA savings, it's only 2.35% worse at 12.35% "real" penalty. If your current marginal tax rate is at least 12.35% higher than your expected marginal tax rate in retirement, you'd actually be better off contributing to the HSA and withdrawing early for non-healthcare expenses and paying the 20% penalty than skipping the HSA.