When I argue with people, I use the term "lockdown" to exclusively mean government-imposed lockdowns.

After we've witnessed the experience of northern Italy in February / March 2020, most informed/reasonable people concluded that the situation is more serious than previously indicated, so it's obvious that people's habits would change. People are somewhat rational, after all.

But arguably self-imposed/-chosen changes in human behaviour can both better account for individual differences (in health, exposure, and risk aversion) as well as respond much faster to short-term, local changes of the situation, compared to government policy.

And the clearest counter example to this ridiculous assertion is the US right now; faced with numbers not seen since the winter the population has only minimally changed it’s behavior over the summer and so far there has been no political will for any distancing restrictions returning.