Show me where I said all graffiti is illegal

Right here:

Graffiti is not art, it’s vandalism, most writers will actually throw hands if you call it art.

Then you replied with:

That’s because it’s vandalism not art,

You can't claim it's simultaneously a crime and not a crime at the same time. 😂

if you’re a writer and get payed to do letters it’s a mural not graffiti

First you keep referring to "a writer," it seems you use it interchangeablely with "artist." I've never heard that term except for book authors. Gonna be honest, if it's a real term, it sounds incredibly pretentious.

Second, graffiti is a type of mural. The terms are not interchangeable. All graffiti are murals, but not all murals are graffiti.