The growth in an HSA is tax-advantaged not just contributions, maybe we are speaking past each other or I am using language not precise enough? I appreciate the extra info about Medicare though.
I understand I cannot be certain of future events, however in the event HSA laws change, they will likely not change so radically (just like they cannot change tax brackets and go back in raise your taxes in the past) I would likely not have significant disadvantages over another tax advantaged account, since it would essentially revert to being traditional (slightly better since I avoid SS taxes). Which is not that big of a deal since I can layer those brackets and will likely have some brackets lower in retirement that would be perfectly fine to fit in taxed accounts into.
