There are many ways to say monks. I also have a desire to make money. Since we are human, we have greed. The world doesn't revolve around just pure things without such desire. The same goes for monks.
However, Buddhism does not allow that desire to remain a mere desire. I never lose my greed, but it is a real salvation only because they make me aware of it and constantly ask me questions.
I studied from the desire to win and be praised by others, and I learned that my own self was broken by Buddhism... the desire to make money, to have fun, and to play was broken by Buddhism, and that thought was within the framework of suffering.
Rikyo, Naimon, Katsu, and the other self are broken and revealed by Buddhism. It is Buddhism that saves oneself. They don't save me by losing my own desires. This is the teaching that comes from my greedy self.
As you said, if you simply make money, another job might be better. But what is it... I can't say it well, but even so, there are things in Buddhism that make you want to live as a monk, or maybe there is an aspect of being a monk because it's not easy to do another job, and this is also not pure.
So why are monks doing it? If asked
“It's a coincidence (coincidence)”
I can only say that. Everything is selfless and impermanent. In other words, it's conditioned. There is no absolute free will.
My desire to become a monk, and even now that I am doing it, it is a gift due to various conditions.