If more than half of the population makes at least double what they need to keep themselves from starvation, then you could argue there is enough money.
In short, your disagreement with the GP is probably due to a disagreement about the lifestyle that UBI is supposed to afford its recipients.
Those in power might determine that the bare minimum UBI to avoid violent revolution is something like $5000 per year.
It's absolutely enough for housing if you squeeze in.
Healthcare and education are problems, but I'm not sure they're enough to provoke a revolution when everyone is otherwise well-fed and sheltered from the elements.
If more than half of the population makes at least double what they need to keep themselves from starvation, then you could argue there is enough money.
In short, your disagreement with the GP is probably due to a disagreement about the lifestyle that UBI is supposed to afford its recipients.
Those in power might determine that the bare minimum UBI to avoid violent revolution is something like $5000 per year.