People at risk of starvation or homelessness are indeed in exceptional life circumstances and need urgent assistance. This is a matter for social welfare programs. Most developed countries already have such systems in place.

UBI is not a welfare system. It is universal by definition. Most recipients of UBI are not in the dire circumstances you described.

So let's talk about the real beneficiaries. I see no reason why a software engineer or a doctor needs an early retirement scheme that allows them to quit their job on the graduation day.