Welfare cliffs are caused by flaws in how they are calculated with respect to income, not their magnitude. Now, what does your comment have to do with that? Care to elaborate?
The U.S. welfare is multifaceted. Try to shift to a stack oriented model. The real picture should include both indirect subsidization and multiple direct benefits/subsidization. Income, rent, food, medicine, childcare, transportation, utilities. There are what someone in poverty would consider sweet spots under certain conditions.
Now, Not all welfare programs stack. Local cost of living changes the stickiness point. But, imo, the most overlooked problem is poor people get good at being poor. There are ways to exchange benefits and untaxed labor for value, even if it's not explicit or monetary.
I've lived it. I know people who are scared to lose benefit X if they earn over Y. The bigger problem is that the government can't manufacture meaning and purpose no matter how much cash they pour out. No marketable skills develop, no local capital accumulation, no gaining experience and moving up. There are no good jobs to escape to. The cliff is doing what you know. What you consider unlivable is life for a lot of people.
Also, I can give some sweet spot scenarios if you want hard numbers.
It's the first sentence of the link guys, come on.