You constantly speak as an authority in COVID yet I rarely if ever see you present evidence for the absolutes you present. Therefore, I can't even contemplate what you are saying because they are just words with no meaning.
I was just at the grocery store in Anaheim and had to wait for my groceries for 15 minutes. In that time, I noted approximately 75 people come and go and noted only 1 person without a mask and 1 person with it below their nose. My brother went to the store yesterday and noted all people wore a mask. Prior to the mandate, there were several people I would see without a mask in the store. There were several items noted in the pull back and one of them was mandatory masks.
What's so hard to understand? I don't have time to survey the world for you. But it's clear that at 15-20% something happens and it slows down. We see it repeatedly in New York, Sweden, Spain, Italy, Belgium. I'm not presenting an absolute explanation as to why: I've told you my theory....it's math. But the truth is we don't really know. There's also no proof that government measures in California are causing the bend in the curve because you are now committing the correlation logical fallacy: correlation is not proof. It's possible government interventions are helping to ease the curve. It's also possible that government interventions are just a coincidental timing in response to things getting worse. Lack of government intervention also doesn't cause an acceleration because Norway and Denmark have no mask mandates but have not had an explosion in cases. You are well versed in the data, but where you struggle is the application of the data (maybe you never took a logic or reasoning course...don't know why you have the blind spot).
If the mask mandate was effective enough to eliminate things, by your own chart things in Los Angeles would have been under control weeks ago and there wouldn't have been a second outbreak in Japan or the Phillipines. They may help on the margins, but it's not enough to stop things. The studies on a marginal basis have been mixed, and those pro assume ideal usage. My own opinion is they probably help, should be part of the tool kit, but in and of themselves are not enough to bend the curve. In the park today I saw a bunch of people sitting under trees by themselves wearing a mask....seriously people if you are by yourself and isolated it's not going to help you at all.
If you want to do anecdotes, from my sons' peers experience I'd say about a 1/3 right now are disregarding all social distancing limitations (full blown get togethers even sleepovers, scrimmage games, physical contact including making out), about a 1/3 right now are being cautious (distanced picnics, small limited 1 on one contact), a 1/3 are still hard distancing. I'm still inclined given what I've seen of the parks, the protests, the beaches, and the kids mingling, the governors order restricting haircuts, restaurants and bars is doing little. Even at the pub down my own street, it was jammed last night again with 1/3 of the neighborhood very little social distancing going on and everyone having a party. But I'm also open to the idea it's possible that in combination with mask usage, people being a little more freaked out, the protests dying off a little, and the reclosures of businesses it's helped. In Florida, Texas and Arizona their restrictions aren't even as severe as ours and they are seeing a similar bend....why....we just aren't sure at this point (but no where in the US outside of maybe NYC is the hellscape that SoCal is right now).