Can a younger person on SSI have a RV as their primary vehicle & residence, travel around, but still collect benefits?
I can think no reason why not. Many elderly people do so and are not in great health. Perhaps a partner helps them. Maybe their disability is more mental. Being on SSI does not condemn you to being an invalid.
When my son was diagnosed with stage 4 cancer the doctor deemed him disabled and he was able to receive SS disability benefits. When he was feeling good he did all kinds of things - rode a 4-wheeler, went boating, took the kids swimming in the lake or hotel pools, he even took his son ice skating.
I think the problem comes in when people are supposedly disabled with back problems, etc and are caught doing things that their back problem would prevent them from doing - especially when a workers’ comp claim is involved.
SSI (Supplemental Security Income) is not the same as SS Disability Insurance (SSDI). SSI is determined by disability or age (65+) and limited or no income and savings. SSDI is determined by disability and work credits. For younger people, those receiving SSI would have been disabled before they reached working age. If they had worked they would get SSDI based on their work history; only if their SSDI benefits are low enough (and they meet the asset requirements, such as savings < $2K) would they qualify for both (but the SSDI would reduce the amount of SSI received). It is quite unlikely that anyone with any significant work history would qualify for SSI.
You might run into problems with other benefits that go along with SSI. Many states give supplemental payments to SSI recipients and most if not all provide Medicaid to SSI recipients - but if you don’t have a permanent residence in any state, you may not be eligible for supplemental payments or Medicaid from any state. Even if you do qualify as a resident of NY and get Medicaid from NY, it may not cover non-emergency treatment in Arizona,