The issue is that in the west, and particular in the US, being poor is considered a character flaw. Rudger Bergman goes into a bit of detail on the history of that perception, which he attributes to the opposition against Nixon's UBI (at least in the US).

So what we now have in many western nations is a huge bureaucratic body to prevent fraud on social security systems which at the same time significantly increase hurdles to apply for the programs and what can be done with the help. On the other hand, the bureaucratic support to fight tax evasion especially by the super rich, is typically tiny.