I'm not sure I totally agree.
Personal profit maximization only works to a point - for example, if you get too old, sick or the system rejects you early and curtails or limits your ability to make money.
I don't disagree that money gives you options, but, far too many people wait until they have enough money to give back.
If you give back while you are working (e.g. balancing working for profit vs working for nonprofit, altruistic reasons, etc.) - that's awesome. The challenge there is maximizing the good you can do if you're giving too much time and energy to your profit maximization.
At some point, someone has do physically do the needed good work.
For myself, the calculus has shifted. I personally decided I cannot wait until I have enough money, or I am maximizing my profit, to go out and help people.
I also cannot wait until I am physically or mentally unable to help beyond financial contributions. Also, I cannot afford to work in the current system that drains everything from you and leaves you no energy or time left, only money (if that).
Regarding the inherent maximum scaling limits of one person- I would challenge your thinking.
Power laws of networks may demonstrate that helping a small number of the right people might be enough to unleash the butterfly effect or play into ongoing changes.
Also, the physical limits of humanity on one person apply to a billionaire as much as a person with little money. I'm not saying a billionaire, millionaire, or person with significant finances isn't more mobile/capable, but it's not a given.
I am for reasonable profit and balance. There is nothing inherently wrong with maximizing profit if someone chooses.
But if we all spend our time on maximizing profit, there still, for the time being and probably well into the future, still needs to be boots on the ground doing work that is not for profit.