As charity funding is effectively a closed system, excessive contribution to Wikipedia is to the detriment of other charities, with minimal net benefit.
If you think one charity is more deserving your money than Wikipedia, then you are free to decide that with your resources.
You decide how to spend your money and Wikipedia decides how to spend theirs.
Resource allocation is not a solved problem and it is inherently political.
If you're working in the field, you have a perspective of what resources you need to do the job properly and it's always higher than what people outside the field believe.
Were the situations reversed (you were Wikipedia), would you believe what you do today?
If you could do it cheaper, why aren't you?
Wikipedia (the online encyclopedia) can be the best in its class without the Wikimedia foundation being beyond criticism. 99% of what makes Wikipedia great was already there a decade ago, with exponentially less cost.