To your point, how funds get distributed could be up for debate. Maybe instead of sending them to everyone, some kind of productive work that benefits society is required, and the fund would provide a way to get paid for work that normally pays little to nothing. The problem with this, is that the administration of such a program is expensive, error-prone, and full of bureaucracy, just like most other welfare programs. I'd like to think something like UBI would replace most of the other programs, to dramatically cut administration overhead for the countless programs that exist today.
UBI is a better way to accomplish that! The alternative, and what we currently do, is to means test people to determine if they are worthy of getting assistance. The problem with that is:
1. someone has to do the means testing, so you have to run an expensive bureaucracy to administer that testing
2. people might be needy in different ways, so you create multiple of these bureaucratic programs to cater to different types of need
3. now, in order to get help, people have to navigate multiple bureaucratic programs to prove their need. This ends up missing people who need help the most
Think of UBI like a tax credit for people who work and an assistance program for people who are unable to prove their need -- all wrapped into a single efficient program with minimal administrative overhead and minimal paperwork.
There are some people that will do hazmat cleanup for the love of the game, but probably not enough, for example.