Yes, because the amount the US spends on welfare is a smaller fraction of the whole budget. For example, the US spends around ~$100 billion on food assistance [1]. Wikipedia estimates that all non-medical poverty assistance accounts for around $400 billion of the US budget [2]. Increasing expenditure by 10-20% (or even 5%) will almost certainly have a noticeable effect on poverty.
Yeah I don't think increasing welfare is really the solution to ending poverty. Lots of evidence that welfare actually prolongs poverty, not to mention the waste endemic to bureaucratic administration. How about instead of taxing individuals we tax corporations to incentivize paying their workers more?