I don’t understand why any decision maker in any business in the USA chooses to offer their employees (and hence themselves) health FSAs at all, especially when the much superior in every way Fidelity HSA is available.
As someone who does deal with enough medical stuff to clear the deductible (and sometimes the OOP max) on their normal health plan annually, it’s still much more convenient, again because the money is all there at the beginning of the year when the expenses are highest
HSA is funded as you go
"To contribute to an HSA, you'll need to be enrolled in an HSA-eligible health plan, also called a high-deductible health plan (HDHP)."
[1]: or so it seems, I tried to figure this out earlier in the year and the data is just lacking in order to make a perfect decision.
There are cases where it doesn't make fiscal sense. One employer covered 1x premium/employee(spouses and kids were full rate).
And it's a time suck.
If your employer is shitty and doesn’t offer Fidelity HSA, you can also easily rollover the HSA funds to Fidelity every year to avoid the fees.
The coverage for HDHP plans is the same, since it’s the same insurer. The only change is deductible/copay/oop max, which is offset by lower premiums and higher cash flow for younger/healthier/higher earners shouldn’t matter.