[bobthepanda]

Americans don’t use such large sums of cash in transactions very frequently, do others?

The only large exception I am aware of is dispensaries because banks don’t want potential drug money laundering charges.

[kube-system]

A significant portion of the US population uses cash for everything. Only about 2/3 of Americans use traditional banks for their finances. Most of them are poor, so they're not making many transactions over 10k, but those people will pay for cars, rent, etc in cash.