The private financial company—which you don’t get to choose—gets its cut as well, in fees, some which are hidden.
Not disagreeing with anything, but people should know that even if you’re locked into a crappy HSA provider through your employer, like BenefitWallet, you can and should still open an HSA with a good provider, like Fidelity, and max out and invest contributions there.
Just don’t forget to save all the receipts for out-of-pocket health expenses.