Weapon customization depth suggestion?

I’m wanting to make a game where it’s open world but simultaneously pvp will come into afect allot it’s a personal concept.
My question is where do you think the person or should a person base on they’re project how deep the weapon customization is?
I like stuff being realistic and very realistic(ingame computers with webbrowser for example) and dynamic.
But should I go as far as to make it as indepth as a person can crate there own weapon with parts instead of just picking a gun I need help finding a medium in the concept delima.

One of the first rules for gamedesigner is to find a golden point where game is not going to be extremely complicated and thrilled with hundreds of mechanics.
My suggestion is to make it simplier in customization, but more accurate in open world connections.