You can think about i what you want it’s your character but there are several interviews where the devs said v is an avatar for the player you can find a video too i think the devs name is miles(Nice guy by the way).There are some things in rpgs which are set like jobs,what is your goal etc so limitations are always there but with v you have more or less a blank slate.I think your alias is just there so people can refer you with something or also to hide your true identity. Topic:What would have been cool if your voice would change to more a robotic one if you’re full of implants.Well, devs stated some things that ended not being true either by being changed during development or other reasons (like perceived fun).
And actually yes, V is less defined than Geralt as you can choose how V looks and a little about it's background, but that's it.
You'll still be doing things not because you wants to, but because V wants to. You'll still be spending time with people you don't know nor you care about, because V does.
I personally think as V as just a step in the good direction, but by far not a persona I create and even less my avatar to immerse myself in another world.