>I can’t see how charging less would help with running a sustainable business. I would imagine charging more would help with that.
I believe you focused on the wrong half of the sentence. This is the part that they mean:
>that benefits as many people as possible.
The benefit is the utility people get.
So say you run a matchmaking app. You can charge $500 to create a happy couple and create 1,000 happy couples (you have just 1,000 customers worldwide) or charge $1 to make a happy couple and have 75,000 happy couples.
If you look at your profit, $500k is way higher than $75k. Plus you only have to deal with 1,000 users which you might do by hand whereas 75,000 overwhelms you personally so you have to hire dedicated customer service reps. The 75k users require bigger hosting and service fees.
At the end of all this you net just $20,000 from your 75,000 users whereas you would have gotten $450,000 if you had charged $500.
So why would you pick a $1 price point?
Because you enjoy hearing from the 75,000 happy couples you created, getting sent their wedding pictures, heartfelt thanks, etc.
You think you are giving a service, and you'd rather give it to 75,000 people than 1,000 people.
That's what OP means by "help as many people as possible." The higher the price, the fewer people can afford it. If you want your app to help more people, you have to lower the price.