A note from a reader:
It's a significant change. And not one that can be made up for simply by cautious people wearing masks while others do not.
First, I hope everyone will remember that mandates are ultimately the result of weighing science with political and economic factors. The evidence for universal masking has not suddenly changed; only the politics have. Specifically one judge issued an opinion. That's all. Universal masking remains as strongly recommended by experts as it was last week.
Confusing the end of this mandate for a change in medical advice is widespread. Even President Biden said yesterday when asked if people should wear masks on planes, "that's up to them." The correct answer is simply, yes. Most disease-preventing behavior is not mandatory, and that doesn't necessarily bear on the strength of the recommendation—you can legally do all kinds of dangerously ill-advised stuff—only that a political decision has been made not to require it, or not to police it, and rather to have an honor system and hope that people will act thoughtfully.
Since so many people are tired of doing that, we're back to thinking about individual risk calculations and decisions, which aren't the proper lens for a problem like this. But, here we are. So, here's how I'm thinking about it.
The ventilation on planes does work in our favor. As you've surely read a million times by now, the air is circulated and filtered constantly, making the space much safer than it would be if that same number of people were sitting in a typical room. In that case, without good ventilation, one infectious person on the other side of the space could mean you get infected. In planes, we haven't seen that. (It's more likely to happen in the process of getting to or from your flight, or after you arrive and go out to all the other places where no one is wearing a mask.)
But the people in your immediate vicinity on a plane are another story. No amount of ventilation can make it risk-free to sit shoulder-to-shoulder with another person for hours.
Universal masking is helpful because, even though many people are clearly wearing sub-optimal masks in sub-optimal ways, surgical and similar masks do help to minimize the amount of aerosolized virus that an infected person is spewing into their environment. They aren't perfect, and their value is determined largely by how well they're worn. Many people seem to be trying to wear them in ways that render them fully useless. But the concept is that if everyone is wearing one—as well and as often as possible while around others—the collective effect adds up, and you're simply less likely to inhale someone else's particles in any given breath of air. So, by contrast, absent masks, we should expect more virus to linger wherever people are breathing.
N95 respirators are more reliable medical devices. Used properly, they can bring your risk of any respiratory infection infection down significantly (hypothetically by 95 percent, as they are, by definition, designed to filter that percentage of particles in air, though the studies required to get an exact number for SARS-CoV-2 transmission would be unethical in design). But based on real-world usage, we know that these masks allow doctors and nurses to work closely with people in the most infectious phases of COVID, day in and day out.
That said, N95 respirators are notoriously uncomfortable to wear for long periods, as that's not their intended use. Long-term wear is known to give some people headaches and bruises, and documented to lead to more "subjective perception of discomfort" compared to surgical masks. If someone tells you they don't mind wearing an N95 all day, I'd worry they're not wearing it correctly. In any case, it's far from an ideal scenario to have to advise everyone who still cares about avoiding COVID to wear an N95 respirator for, say, an entire four-hour flight. Even honorably attempted, people do need to eat and drink occasionally, and doing that in a place full of maskless people is simply a higher-risk proposition than if everyone else were wearing at least a surgical mask.
That's a hypothetical aspiration, but a 2020 meta-analysis of surgical versus N95 masks did conclude that the two could be comparably effective at preventing respiratory infections. In the authors' discussion, they speculate why:
Point being: By quitting the basic practice of wearing a simple mask when in close quarters with other people, we are declining to collectively make a modest effort to help prevent some disease. In doing so, we are placing still more burden on those at highest risk and those most conscientious of others. We are making spaces less safe for them, telling them they can wear respirators or avoid public spaces if they feel unsafe, as though this were simple or even possible, while the rest of us can't be bothered to do anything at all. It's a shame, but it's what we've done again and again throughout this pandemic.
So I realize I'm not answering your question about LA specifically, but I hope this is somewhat helpful in thinking about all this as you decide. I'm not canceling trips, personally, because I've been very cautious and will continue to be. And though this writing has been pretty negative, it continues to be heartening to see others who still care and are just trying to make sense of this jumble of science and politics. You're not alone.