Only if they are not supported/taking medication that helps them, etc. If you do better in the general society, do not harm yourself or others taking medication, then not taking it is just dumb. You do not have to take it but you are likely to be/act out your illness if you do not and society cannot afford that.

No one likes taking medication or likes the current side effects, etc. but, for right now, I have to take my thyroid pill and have to use my asthma inhalers and go to the ER when they're not enough, etc. I had to take the antibiotic that later got a black box warning or, at the time, I would have died.

Just because one doesn't like medication and doesn't want it, one can choose not to take it but there are always consequences of not doing so; in the case of severe mental illness, you may no longer be allowed to go out in society where you are threatening people or causing other problems. If you are not threatening people (including yourself) and causing problems for law enforcement or your family or whoever has to deal with you in a bad state, then it becomes obvious you don't need the medication (or are taking it).

It's not a whole lot different from people who are suicidal; we put them on suicide watch. People who are threatening or acting out, we put them in jail or mental health situations where meds stop the acting out. No one gets to endanger or ruin other people's lives to live their own any way they want. If you aren't 18 or whatever age to be held responsible for yourself, your parents get a vote; that's just the way it is. If you love running nude down the middle of city streets, you get jail or a mental health stay, depending on what is going on in your local society at this time; it's just the way it is.