It's very idealistic to think that giving a household the cash will give them the opportunity to organize it all and use the money maturely on their own. When you're living check to check, for many people that means that they don't have legitimate savings and from experience, you're always catching up to insurmountable expenses that seem beyond your control. Let's be honest, it is safe to assume that a large amount of people that would qualify for the minimum income would not be able to handle their money enough to supply themselves savings for health care, let alone retirement. Now, if Mincome was to substitute govt-subsidized health care, that means those people would, well, not have govt-subsidized health care, meaning they would not have any health care at all. And that is very bad for the society as a whole, not just the individual.
I don't think Mincome though is the end-all-be-all to guaranteed income plans, just a place to start thinking of ideas. There is a tremendous amount of waste in bureaucracy, giving cash directly to people allows them the ability to individually tailor plans to their own needs. You could even set something up of a transitionary period where recipients could chose between the current welfare system(food stamps, etc.) or guaranteed income. We also have to consider that our current Welfare system in the US suffers from a phenomena known as the "Welfare Trap" where recipients are essentially penalized for trying to seek higher forms of income, as it puts them in danger of losing welfare benefits, resulting in a net loss of benefits received. The Welfare Trap is a real thing that plagues our welfare system(as well a bureaucracy waste) and is a symptom of an engineered plan that doesn't effectively complete the objectives it was designed to fix. So regardless if we switch to a guaranteed income system or not, our current Welfare system is something we should not settle for, as it has obvious areas that require improvement.
No doubt, which is why despite the blatant risks I think we should try to at least test-run any option we can, a modified Mincome concept included. Even combining them to include health care as an automatic deduction from the income value just like a company will do for its employees. I don't know, I think if we're failing anyway we may as well take the risk of crashing a couple projects and test-runs in the hopes of finding something effective.So regardless if we switch to a guaranteed income system or not, our current Welfare system is something we should not settle for, as it has obvious areas that require improvement.