One might ask in a first place : who needs $10,000/month to live (including water, food, private place to sleep, and some entertainment) ?

If some people can live with $1,500/month, how come other receive so much and for what?

I guess it's related to "capitalism", "liberatism" or whatever. But please can someone explain to me like I'm five ?

Adding value. Lets say there is something in your life that you care about and costs you $100 a month. If I find a way to provide you with the same value for $20 a month and manage to do it at a cost of $10 a month, if I can persuade you to do business with me, you get the same value for $80 a month less and I get $10 a month in profits. If I manage to convince 100,000 people to also save $80 a month, I get $10 * $100,000 or $1m a month - not by taking away from others, but by saving them money.

Of course, plenty of people get money in ways that doesn't align with this ideal, but as an entrepreneur, that's the way I think about things and I have no problem with receiving $1m a month if I do so by saving others money and/or providing them with goods or services that they choose to purchase and that makes them happy.

What a single person can live on may be quite different to what a family would need, especially with school age children.

Some people might be happy living a simple life, some may want the fancy house and car, or want to travel whenever they can.

>who needs $10,000/month to live

Those who have a monthly mortgage payment of $9000. Substract $500 (or more if the government doesn't help you with their costs) for each child in your household.