"China did actual lockdowns." Yes, they did, and literally made prisoners out of their own people. Which had the unfortunate consequence of killing people for lack of care, food and social contact.

"Herd immunity? Never happened because infection isn't preventing reinfection with a different strain." This is exactly wrong. Once you get covid you may contract a different strain, and if you are a normal healthy individual it will be like a bad cold, if you have symptoms.