Disclaimer, I am 1) talking about the US and 2) talking about the current laws not what I think the laws ought to be.
You have to pay taxes on income.
You also have to pay taxes on gifts.
Say someone gifted you something incredibly valuable, like a house. You have to pay taxes on that gift.
Say you don't have the money to pay taxes on the gift, then what?
Say the gift-giver of the house is also willing to pay your taxes.
That would ALSO count as taxable income which you would need to declare and pay taxes on.
Essentially, it's illegal to give things to people whose cash on hand is below a certain threshold.
Free market is about trading freely with others without outside interference. Fiat currency and government strongarming has destroyed this system into cronyism. Not capitalism itself.