I'm not sure I share your perspective that if a person makes $1 selling something valuable to 1 person, they are moral but if they make $1 selling to 10m people they are now immoral unless they give that money to someone else without an exchange of value (charity)
Good, because that's not what I said at all. :-) I was using the example of someone at one extreme who has no bandwidth for "helping others" (financially or otherwise), and someone at the other extreme who has a huge amount of bandwidth for "helping others." That "helping others" isn't "by selling them stuff." Point being, both extremes do exist, but the inflection point in the middle is fuzzy and squishy and hard to pin down even if you are being genuine about it.
Do rich people have a greater responsibility to fund things to improve the world?
Yes.
Someone making only $10k is not only poor, but most likely their sense of purpose, meaning, healthy pride, belonging, and usefulness to society has diminished and would be in a better place if they added more value
Be careful there; you're drifting into an extremely Amero-centric "Protestant Work Ethic" territory there, which is both myopic and harmful. :-)
If you work 60 hours a week to make ends meet, you get the "pride of doing work" but... have no capacity left for "tending to yourself." If someone in that situation isn't tending to themselves, it's frequently because they can't, because of systemic blockers in place that don't allow them that opportunity. For those who do have sufficient capacity to help others, addressing those systemic blockers so that others have the opportunity to do whatever self-work you're talking about is highly valuable. Not in a point-counting capitalist understanding of "value" but in a social-emotional sense of creating net-positive goodwill in the world. Which may indirectly have a 2nd or 3rd order effect of more capitalist-value down the line, but that is not the point or goal of it.
To turn to someone spending 60 hours a week barely making ends meet and say "you need to tend to yourself" is straight up victim blaming.
Also, Ayn Rand can bite me. :-P
But that's how the argument you're making can be interpreted. One activity done at scale changes the responsibilities to society by the nature of the scale? I'm not convinced. If a service is valuable and people wish to pay for it, why does it matter if they pay 1 time, 10 times, 100 times, 1,000 times, etc...?
I'll flip this on its head and say to not help and encourage that person to obtain new skills (focus on themselves) so they can eventually work fewer hours and add more value to their community (i.e. get paid more) is worse. I think they would stay perpetually in a state of victimhood if they don't recognize the value of improving themselves and investing in themselves first instead of working like crazy for everyone else.
You can call that victim blaming if you want, but that mindset is what has broken every first generation rich person out of a state of having nothing to having much.