You can have large knives in checked luggage. I do it all the time.
Someone I know had scuba harpoons in his carry-on and wasn’t stopped until he got to Rome.
Rome also detained another person I know just because she had been to Morocco. She almost missed her flight.
America is known as the most litigious nation on earth. It stops us from doing what we should do.
Somewhat related: Another person I know quit social work after spending all her time fighting lawsuits every time she hired the person she thought was best for the job. She gave up her extensive training and career rather than hire the wrong people or become a de facto lawyer.