It is true that "most people are on welfare a short time".
It is also true that a vast majority of the welfare dollars are spent on the same, relatively few, needy persons. They are needy by choice.
At any point in time most recipients are chronic, and a small minority are short timers, come and go.
So at any moment in time, only a few transients, but as time stretches out, those few become many. So the 20% minority, over a few years, soon becomes the majority.
The 80% majority remains on, year after year, generation after generation, depleting the welfare resources intended for the transients.
I suppose we could say that there must be psychological shortcoming that causes this desire to be needy, but its really much more pragmatic.
The welfare system provides very well for "the needy", the "Poor", the "have-nots". The system does not distinguish between those who are poor by circumstances and those poor by choice. This creates a disincentive to 'get off welfare'.
For the well intended who fall into welfare by circumstances, getting off is no easy matter, it they have managed to adapt even on a very basic level.
Each freebie morsel leads to another, and another, until all needs are meet, with little or no employment.
Those who are born into the system are able to maximize welfare benefits easily, creating a modest but comfortable lifestyle with efforts going not to production, but to handouts.
If one is not born into the welfare system, they will require more innate abilities to adapt to the 'why work if I can have it for free' life style.
When the tipping point is reached - it may take a year or two - getting off is a step down, life is not as carefree. This withdrawal period must be endured, before the individual comes out the other side, and says "Now I am better off."
On the short term, it requires considerable income to replace welfare.
Far more that the general public realizes.
A "good paying job" is certainly not enough.