By the definition of what? "Bias", "own bias", or "human"?

I don't know about "human", but being "biased" is something like "consistently straying from the truth in spite of available information", but there's nothing right there that says that everyone must be biased. In so far as someone is biased, they cannot be free from their "own biases" only in the same sense that I cannot think anyone's thoughts but my own. Still, nothing stops them from trying to improve.

Now, if you mean that we cannot avoid living in some particular information bubble, that's not a bias (at least in the psychological sense). That's an issue of incomplete information.