Yes but no. Yes you can enter carrying as much cash, but no you cannot freely enter with over $10k in cash, they need to be reporter to the US Custom and Border Protection before entering the country https://help.cbp.gov/s/article/Article-195?language=en_US
Does “freely enter” have a legal definition? Because you are “free to enter” but need to declare. Just like you are “free to enter” but need to declare if you have an orange you purchased from the States making a return journey back into the States.
'complete' doesn't mean 'enter the amount of change in your pocket, and small amount of holiday spending money rolled up in your socks' though. GP's right that you only have to declare certain things, a completed form can be 'nothing to declare', which obviously doesn't mean 'I am entering nude with no belongings'.
