Not reduced... just postponed... that your and many other countries have to resort to 3rd or 4th lockdown is a proof of that. Just like masks. Since one is not effective, the current advice is two or even three. As demonstrated before, countries with stricter lockdowns do not have better (and often worse) results than those with more lax (or none). The same goes with strict vs. lax mask mandates.
The problem with statements like this is that it can be shown to be wrong wtih some good examples: Australia, China, New Zealand and Vietnam.
There is now close to 0 community transmission of SARS-CoV-19 in Australia, China, New Zealand and Vietnam.
The problem was only gotten on top of in Wuhan by a very strict lockdown and that worked.
Summary: lockdowns work.
For lockdowns to work there are some essential requirements:
- the area being locked down has to have a reduced number of people entering and leaving that area to critical people only (transport workers for freight, etc)
- people within the locked down zone also need to limit travel, curfews are one way of doing that
- they need to be long enough to get to the point of 0 unknown causes of infection (this can take 2-3 months)
Which is to say that if California went into "lockdown" but still allowed people to fly in from Florida or NYC or Houston then it is not going to be very effective because you've still got the potential for new infection to arrive by plane.
The Spanish Flu was limited to traveling between continents by boat. SARS-CoV-19 gets a free ride on planes that will take it from one side of the planet to the other before a victim because symptomatic.
Mask wearing was part of how the Spanish Flu was defeated.