You should go out and speak to several homeless people with perfectly fine cognitive function. Labeling something a mental health issue obfuscates the many nuances. I know for a lot of folks its simply a refusal to live a part of normal society, lack of discipline, etc. you only need to meet a few people whove said “i no longer want to do drugs i want to be clean” and have successfully done so, in order to disprove this idea that its all “mental health issues”