How does a pledge about something you may or may not do in the future helps poor people today? How does "the majority of their wealth" address income inequality

How does a pledge about something you may or may not do in the future helps poor people today? How does "the majority of their wealth" address income inequality? Will said billionaires give away so much that they cease to be billionaires or even millionaires? And how are the actions of a few billionaires relevant to what the industry does as a whole? Does Google, Facebook, or, God forbid, Uber, address the problems of poverty and inequality (which are separate problems) as a company? To a very large extent, charity is irrelevant; charity is a way of buying oneself a conscience without actually changing anything in the world; without even addressing the problems or thinking about them.