"travel far enough" is the whole point: if you live in a marginalized situation, UBI is unlikely to pay the cost of transport to save money on shopping, and mechanistically, since you don't have a car and cannot pay delivery, you are stuck behind higher unit pricing exploitation.
Unbelievably high numbers of people in the UK now depend on food handouts organised informally. Food stamps and Gated cards for welfare have their own problems. France recently passed laws requiring supermarkets to supply charity food from unsellable ugly fruit and vegetables, and near-dated produce.
Why do you think this is? Why do you think the state is trying to force independent, semi regulated economic entities to perform a social welfare outcome? Now put UBI into the equation. You think this is axiomatically going to fix the systemic underlying problem?
UBI in greece would demand the entire last 15 years historic debt be wiped out. Otherwise, its going to be grabbed by the asset-rich who have been avoiding the consequences of forcing defaults on the non-working poor.