I am not sure if I agree. Govmnt has to deal with much more than mere function of their programs. It must have approval, integrate with other social databases, be somewhat resilient against fraud. Not to mention this assumes everybody can be reached by electronic deposits which isn't a given.

This is pretty much a reasonably solved problem. You issue a bank card to anyone who doesn't have a bank and deposit the funds and resolve issues of identity by physically showing up an an office. Post offices are pervasively available and usually very close to where most people live.

For fraud issue you have the bank or banks running the program handle fraud per normal procedures and the government steps in to prosecute people who abuse the system as they do in present situations. The program loses no more than a normal bank to fraud and covers losses from fraud by investing deposits in safe securities.

Identity fraud is a solved problem (in most developed countries anyway) a bigger issue is false claims and general inefficiency of government welfare programs.

You can just give everyone an equal amount of cash instead but then disabled and other people who are unable to work would starve to death unless there is massive increase in taxes/redistribution.