I don’t understand

I see so many ppl on this app giving their kids nick names or shorting their name before there even born. Why is that? why not just name them the nick name

Ex...

Nicole but imma call her Nikki

Bellemy but imma call her Bell

Everly but imma call her eve

Dont get me wrong im all for nick names I call my kids by their nick name which was given to them after they were born and it has no relation to their real name.

Im just curious of why you choose not to name your child the name you plan on calling them.

No im not talking about bugga bear, sweet pea or chunck monkey im talking bout nick names