This statment can be interpreted in 3 ways.
1. Things only. Humans want endless things.
This interpretation focuses on physical things that people can purchase. Even if you have the best food, a huge house, and tons of material comfort, that is not enough. People will still want more things.
The mountain of gold includes the situation of being the king or supreme ruler. But it goes beyond that to imagine having more wealth than 1000 kings.
Sometimes people take away that the most important things can't be bought with money. Things like love, connection, calmness. But then, it is easy to conclude that the goal is to just get those things too, then it would be enough.
2. Things and relationships and comfort. Humans also want endless non-tangible things.
In this case, people can buy love and companionship. They can buy good health. Take it even further and suggest that they can live forever and never feel discomfort. They have nearly entertainment and comfort. What then?
The quote suggests that they would still want more. Maybe it is a keeping up with the Joneses. Or needing even more entertainment.
People can take away the idea that the mind and desire cannot be tamed. And that would, imo, also be misleading.
3. Look at this crazy mind, that cannot satisfy desire.
This tells you not to accept desire and also not to necessarily try to smash it down. Instead, you try to notice and understand the patterns of the mind. Why do we trick ourselves to really want things/connections; or rather, there might not be an issue with the wanting, but it is that subtle, hidden backstory that whispers, "If i get it, if i get it all, that will be enough". This is, of course, a lie. Once we get it, we get used to it and then want that next high/feeling of getting. Or that goodfeeling goes away too fast.
The Buddha pointed at a way out. Training and calming the mind.
I am not sure if desire totally ends with nibbana/enlgihtenment. But i know that the chasing and the clinging to desire can end. We don't have to feed it.
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There is a parallel to alcoholism. We lie that we just need that next drink, that that next drink will be enough. But then we want more and more. The AA path gives an interesting approach. The desire to drink never goes away. Even if one is sober for 25 years, they go to an AA meeting and are supposed to say, my name is John and I am an alcoholic.
The desire doesn't go away, but the feeding of the desire and having it take over one's life... That ends. That is possible.