I have kids. I love a loud house with quiet time.
Loud children above age 2ish in the movie theater or restaurant are to be behaved because of the proximity of others.
Babies on airplanes get a pass because iykyk
I think broadly if you’re doing something you just need to do, then a kid being a kid (particularly babies) is fine. Even if it’s annoying, that’s just life. Beyond that you need to pick your place - I’m happy taking my young kids to dinner where there’s other kids and noise, I’d not take them to a quiet tasting menu place.
Having said that, someone with an upset baby is probably having a worse time than I am and I can usually just sympathise, sometimes things are more out of someone’s control than you think.
Removing them after a few minutes to talk to someone always feels like I am getting assaulted with noise.
Fell asleep for the first time on a plane and I'm never going back.
The general rule is no screaming without a good reason.
As for those without parenting experience there isn't anything you can do short of killing the infant to get it quiet. They go from struggling to inconsolable which is literally a place where they have to exhaust themselves before they calm down. If the parent could quiet the kid they would.
I've experienced it a few times and despite all my experience and skills the child couldn't be soothed until tired enough to respond positively. In most cases it's less than 90 minutes unless there's a physical reason. Then it can be 8 hours. Bless the parents with children with damaged biology.