Thanks for posting @Dimity a good reminder to people who don't see that side of life, or don't consider it even if they encounter it (such as homeless people near station or shops etc).
I volunteer in a kind of a soup kitchen type place. Many of the people are homeless and many are in insecure or sustandard housing. I see people in all age ranges, men and increasingly women and families.
It would be interesting to know the definitions of homelessness. Are they only referring to people living on the streets (non solid shelter), or does it include people living in their cars, vans and trucks, does it include those couch surfing, living in garages, squatting etc. It would also be interesting to know stats on other deaths due to homelesssness such as infections, chronic diseases, pneumonia etc. Since it's difficult for people without an address to access healthcare. The mortality for homeless people overall must be large. If a young person is dying every 4 days, that's only one aspect of deaths due to homelessness.
I would say most homeless people (I'm including all of the above definitions) have either become homeless due to MH issues, or have MH issues because they are currently homeless.
With the cost of housing increasing, and low housing stock it is going to become a much bigger problem, but as you say only a sub-section of the population seem to appeal to politicians.