i think that when you make art, you’re usually trying to communicate some sort of message or feeling. so when you know who your target audience is, you have a better idea of molding out your intended message in a way that’s easier for them to fully understand. like if you want a five year old to learn about something related to science, you’re probably going to have them do something fun like watch the magic school bus or show them some vibrant comics that help break things down instead of making them watch a five hour documentary or reading a high school textbook.
sorry if my answer isn’t helpful i tried my best lol