My personal opinion is that human nature and relatively complex rules about what is and isn't HSA acceptable, tends to make it difficult to reap the tax savings that the system is possible of providing. I have worked with a number of startups trying to determine whether their offering can be paid via HSA and the rules are conflicting and ambiguous that without tens of thousands of dollars in legal fees (which even then only offer some piece of mind) its difficult to determine.
It's just a very complicated thing for people to have to deal with, an example of a potentially covered item: "Over-the-counter medicines and drugs - Effective January 1, 2020, expenses are generally reimbursable unless used for general well-being or for purely cosmetic purposes. Over-the-counter medicine and drug expenses that are incurred after January 1, 2020, are generally reimbursable. This may include, but not limited, to acetaminophen, acne products, allergy products, antacid remedies, antibiotic creams/ointments, anti-fungal foot sprays/creams, aspirin, baby care products, cold remedies, (including shower vapor tabs), cough syrups and drops, medicated eye and ear drops, ibuprofen, laxatives, migraine remedies, motion sickness, medicated nasal sprays, pain relievers, sleep aids, teething gels, and topical creams for itching, stinging, burning, pain relief, sore healing or insect bites. See Kits and Vapor units and refills."
But then within each of those there are things that are and things that aren't, sometimes based on your intent. All that together is a lot of work considering the limits are $3,650/$7,300.
In particular a phrase like "...generally reimbursable unless used for general well-being..." is the sort of tortured thing you only find in a bureaucratic nightmare like healthcare.