In theory people would have voluntarily dramatically reduced their contact with others. We did see some of this in early March 2020. Such action still would have brought the economy to a grinding halt but really doing it would have reduced spread.I can't think of any logical way cases would have been lower without lockdown.
Leaving people to decide for themselves is always my default preference. But if that is a good and valid position it shouldn’t require lying, misinformation and conspiracies to be the real meat of the argument.