One benefit of middle age is that nobody can call you a child.
Some people do, but they're wrong and easy to dismiss.
"Childish" seems to be the favored way for online conservatives to attempt to disparage somebody's opinion by disparaging the person.
The insult, "child" or "childish," is quite similar to the feminists' use of "misogyny" or "misogynist." These words of no specific meaning are a punch in the gut for most people who encounter them. These are words that dissuade a person from going further. They are in this way a kind of weapon. They're meant to hurt or disable
Pimply kids and young men have "moron." Nobody talks that way to real people. And that's what it's for
These are words meant to function as weapons. They're supposed to stop discussion. They're supposed to finish you.