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.
I generally understand dealing with an upset kid in public is hard and I sympathize. But I once had a red-eye flight where the kid was screaming for its daddy, who we later determined was on the flight just in a different row. We saw no indication the mother was actually trying to soothe the child, nor did she go get the father. We were not happy to start a vacation with such little sleep...
One of my favorite stories is a flight with a mom and a few kids. Her oldest started shrieking at some point, likely due to the air pressure change. The mom said something like (calmly) "there's nothing anymore can do about it, so what do you want to happen?" And the kid shut up
Indeed I never realized how high the level of the background white noise inside a pressurized cabin really is until I started wearing ANC cup headphones in a plane.
Removing them after a few minutes to talk to someone always feels like I am getting assaulted with noise.
I got some earplugs designed for people who deal with sensory issues and they have completely transformed being on a flight from actively annoying to passively acceptable.
Fell asleep for the first time on a plane and I'm never going back.
Thankfully boys grow out of it but girls can hit that frequency that cuts the skin.
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.
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