Gates could pay his entire net worth into the treasury and it does not fix a fundamentally broken system.
Gates is commenting on how the ultra rich like him make most of their money from capital gains, which are not taxed at normal income tax rates. If capital gains were simply taxed like income taxes, it would be a huge blow against income inequality this country is facing.
Because capital gains are taxed differently, the ultra rich will continue to have their compensation geared towards stock, and away from income.
Gates is looking to change an unfair system. He alone can't do that.
It is not hypocritical for Gates to ask for macro solutions to macro problems.
Same thing with your Al Gore example. Leading by example does not make systemic changes to huge, complex systems. That's never going to work.
Al Gore could be living homeless in a tent in a forest and take a vow of poverty. It wouldn't make a dent. Your Gore example is particularly egregious because the No. 1 source of CO2 emissions in the U.S. is from transportation, and the main culprit of that is the sprawl that everyday Americans insist on living in (that the government has subsidized for them).
It doesn't matter if you'll listen or not. Big problems like income inequality and catastrophic climate change need large, systemic changes. There is literally nothing you the individual could do that matters -- except supporting government and system changes that push us forward.
US GDP was $19.39 trillion in 2017. 0.01% is micro on any scale. He could write those checks again and again and it would never solve systemic problems.
Now, ladies and gentlemen, this is a platitude.
Great, but that does very little to solve the problem. Everyone needs to slow down, not just one car.
If you drive 35, and you're legally allowed to, all cars behind you will also drive 35 when they reach you. Unless they can and may pass you.
Like I said, leading by example. People copy other people's behavior.