By the sound of your resistance to my original comment though, no amount of sources will prove to you that the measures taken saved lives.
Remember, they weren't really full lock downs, they were these partial kind of lock downs. Even in the US, some places did curfews, some did not. At the very least, you have to admit that there have been some measures under the lock down umbrella that were not as effective as others. If you can't even examine your faith in your statement, you are right that there is no point in discussing this subject further.
That's the entire reason why the Tri-State area worked together to create and follow each other's lockdown policies.
If you have a piecemeal approach, people will flee the lockdown and bring the virus to wherever they go to continue the cycle. The lockdown (and masks) only work if you have high levels of coordination and compliance. That's why having a national policy is much more effective than a regional or state-level policy. That's also why China was much more effective (from the outside, if you believe anything about their numbers) than the West was.
Also, Sweden, Florida.
Strict lockdowns may make a difference, but given the fact that 40% of the population just can not work from home, they're never really strict.
For me the 'undeniable' part of your statement was far too strong.
Also anecdotally, having lived in NYC through COVID, can confidently state that without the city going on lockdown (and it was by all means a strict lockdown), hundreds of thousands would have died.
[1] https://www.nbcnews.com/news/us-news/florida-data-scientist-...