Working for a capitalist is voluntary.

Hunger makes it mandatory for the largest percentage of the population.
Yes, people can exist outside the crapitalust paradigm.
No, it is not an option for the majority.

In an anarchy one could choose to work for no one or even set up a cooperative.

Under anarchism, if you become known as a bum you are not gonna like what happens next.

Now i argue in a statist world working for others is not volutary we are not allowed to provide for ourselves nor transact buisness freely.

Very true, who finances the state?
Crapitalusts.
The state, as we know it, could not exist in a voluntary society.