Because Lego isn’t valued on scarcity.

What would be the real-life equivalent of buying more LEGO then?

Lego is the end product. Not something you use to claim scare resources. So it would be like printing more oil or housing. Once you reach that point you are in a post scarcity society.

In this situation, the issue is that there aren’t enough nice pieces for everyone. At some point there become enough that without being insanely greedy that everyone can have some.

imagine living in this mindset constantly and being unable to turn it off, even when talking about kids playing with legos

You mean it’s not relevant to mention economics in a discussion about children who invented an economy?

not everything has to be an analogy to your geopolitical worldview especially with regards to children playing with legos

"mom can I have some more spaghetti?"

"oh sure, let me just call up the Federal Spaghetti Reserve and ask it to print up some more Spaghetti Dollars, thus only further increasing this nation's Spaghetti Inflation far past manageable limits—great idea, if you want to usher in complete economic collapse!!"

like come on