Should sexual identity be a private thing sometimes?

This may seem insensitive but when I think about kids for example coming out, it seems inappropriate. I am omnisexual but it doesn't feel necessary to announce who I like to have sex with. Sex shouldn't be so taboo bit it feels weird for a child to state something sexual as a part of their identity for example. Another example is coming out to coworkers. What is the point unless you're trying to hook up with them (if it's a sexual orientation)