Is it weird or not people hide their age?

Okay I want to see people's thoughts on this matter bec some people say its weird most people will hide their age bec it isn't such a "private matter" but some also said minors could be targeted by ped0s which is understandable but it's also weird if they're an adult who's hiding their age. I wonder why this is such a debate bec personally-

I've been friends with this person for 3 years and I still don't know how old they are. I know they're minor but what if they aren't? It's concerning to me honestly I respect their boundaries but we've been friends for a long time I have to know atp.

My opinion I want to know if the person I'm talking to is a minor or not cus my boundaries between an adult & minors are different. Certain age to me has diff boundaries so if ur under the age of 16 best know I'm not gonna be that close to you cus I tend to overshare or be overwhelming (working on it btw)