I don't think you should have been downvoted because you appear to be trying to find out why this person doesn't have a home. I am not the poster, but here's an example of a plausible answer. (Apologies for the lengthy post)
You have $50K in collections debt, no insurance, no credit, no bank. Any money you have, you carry with you.
Getting paid is a pain in the ass, because even though you could conceivably receive money through an online service that does not require a credit card or bank acct, actually extracting the money as cash is quite difficult. Nobody wants to Paypal a client, anyway, and nobody wants to learn how Bitcoin works, much less figure out potential tax issues. You apologize profusely for making the client send you your fee via Western Union.
You pay for a prepaid cellphone. You need internet with a sizeable data cap, which isn't very affordable or reliable via mobile, so your first stop for internet is probably libraries or cafes, which you can only work at for a certain period of time before you're not-so-politely asked to move on. Just getting your work done or having a regular video call can be troublesome.
You carry your possessions with you, and the more you carry, the more homeless you look, and the more homeless you look, the more people have a kind of ick-response to your presence and want you gone. If you ever have to put your stuff down for a moment you risk your only valuable possessions disappearing.
You don't have enough yet to cover first, last, and security on an apartment, but that doesn't matter anyway because nobody will rent you an apartment without proof of income. You have no permanent address, so getting billed (among many other things) is an issue. Your options for housing are dangerous and filthy weekly or monthly rate rooms in the equivalent of a halfway house or crack motel. A shelter is sometimes a better option, when a bed is available.
Getting to your semi-housing is not easy, because it's invariably located on abandoned stretches of US-1 or a highway (and obviously you have no car). You are very lucky if there is public transit that goes from your shitty motel to a place where you can use wifi regularly. You may have to pick between paying for taxis (no, Uber doesn't run out there, but will charge you a pretty penny to take you there) with the little money you have, or walking a couple hours each way. If you have an in-person client, you obviously need to be presentable, so now you're spending as much as you can on a place with a shower, taxis to and from the job, and maybe an upgrade to a place with wifi.
All of this for basically one or two clients that occasionally hand you a small piece of work at a very-sub-standard rate. Because of your bad credit, lack of recent work experience, lack of a bank account, lack of transportation, etc etc, few people want to work with you. When they do, the work is infrequent, and done when you can actually get to doing it, due to the aforementioned impediments.
You pray your stuff doesn't get stolen, that you don't get mugged, that you will get another contract soon. You don't haggle over payment because you're lucky someone will deal with your awkward payments, and what if you lost that client and had to start over? Without some kind of miracle, there is no math that puts you in stable housing any time within the next year.
The answer "It's complicated" isn't satisfying, but it's often reality.