Ignoring the irrelevant factors of legality and the concept of "private ownership", is being a "thief" who "steals" as a living, really any different in principle from being a Hunter-Gatherer?

Essentially, both take by force from other participants in the competition to survive, without regard for the fate of the other.
The berry bush gave no consent to have its fruit forcibly taken, nor did the deer agree to be killed and eaten.