The negatives are real but if you have few to no options van life may be a joy compared to living in a tent or cardboard box or homeless shelter or leaning against a cold cement wall of a building with plastic draped over you to fens off the wind and rain.
Some folks live in a van by choice. From what I have seen there are van-dwellers who do have options but those are generally few and involve sacrifices. I have considered van and small RV life. Being able to hook up to electricity and water/sewer would ease daily living and offer much more comfort than doing without those luxuries. A drawback to that lifestyle is finding a place where the hook-ups can occur and then what type of environment are you immersed within. There are small out-of-the-way trailer parks in many towns and cities catering to a generally low-class clientele’. Usually found in the “bad” parts of towns the run-down appearance of the place and most to all the units within those low-cost hangouts are frequented by police and drug use and uncivil anti-social behaviors are common. Noise also seems to accompany that low-class cohort. Barking mutts and noisy squabbles are the norm. BAH!!! I am not that desperate to live among savages and barbarians!!!
A small RV is hard to live in inconspicuously. Not impossible but you may need to be constantly moving it to avoid notice by citizens and police. Trips to drain and fill sewage/water tanks are needed. Electrical power can be problematic though some folks have solar power and engine power to charge batteries specifically designed to provide power to the living area. That stuff gets expensive and reliability can be a problem.
RV parks exist with short and long-term stays. Prices vary a lot. If you have a regular income a low-price place may be affordable. Pluses and minuses vary when living in one of those RV specific place.
There are a multitude of considerations regarding van/RV living. From the vehicle itself to where to park it and how to make your life as comfortable as possible and all of this is dependent upon how much money you have now and of you have a steady income source.
Here is the video that covers just a tiny part of the consideration of van dwelling.
Alternative Living Options 