This isn't how taxes work. If you donate money then you've only reduced your taxable principal. You "avoid taxes" in the sense that it's as if you never made that money. You don't magically reduce your burden any further than that.
People won't take your otherwise fine point seriously if you include this commonly made error.
They can't further "any" goal they want, it must be a charitable goal. Bill Gates can't take money from the B&M Foundation to buy himself a yacht. I don't really see what your point is. Anyone that donates money is avoiding taxes to spend money on something they want, where "something they want" is a charitable goal.
It's a common mistake that bothers me because it often is used to dismiss (or even demonize) what is, in the majority of cases, an altruistic act.
Chartiable donations can also come with requirements around evangelism which I personally find aborrent and, as has otherwise been pointed out, yes it's an absolute reduction in take home but abuse of the system is rife and the income reduction mechanic makes this really attractive to some folks if they're hit with a particularly hard year.
In Canada I've actually been pleased to discover that your retirement is mechanically a charity - investing into an RRSP (registered retirement savings plan) counts as a direct income reduction which can mean that swing years when options may be cashed out or other windfalls happen - can be put profitably towards your own future well being while also ensuring you don't become a burden later in life.
It's worth reading that entire well-reasoned and well-researched post, but the tl;dr is that many billionaire philanthropists do a lot more good per dollar spent than the government and they get problems solved that government is often incapable of solving.
Plus, a sizeable portion of every tax dollar goes to the military, so tax minimization helps reduce how much goes to the war machine.
The sort of TL;DR here is that America being the world police isn't something the public approves of and I think it'd be more efficient to pursue addressing this point then hanging your hopes on billionaires. The utter fascination and praise of billionaires is an extremely toxic[1] spin off from general American Exceptionalism which has done quite a lot of damage to... well... Americans actually being exceptional.
1. In my opinion - how you view the effect of this on society is entirely an opinion thing.
[1] Note that a 200% penalty rate can apply to uncorrected self-dealing transactions. For the board members and officers, an excise tax of 10% may apply, which the non-profit cannot pay on their behalf.
One of the reasons I'm working hard and saving money is to provide my family with better opportunities than I had. To say I'm not allowed to better the lives of my family is to deprive me of rights and freedoms to do what I want with what I create.