Depends a bit on your threat model I suppose. Journalist protecting a source? Probably helpful. Getting mugged? Helpful for preventing ID theft, but potentially increased risk of physical harm. Political dissident covering up regionally unprotected speech? Obstruction charge may be less harmful than the alternative. Wall Street trader shredding insider trading documents? Obstruction charge may be worse.

This is a gross oversimplification but shows how it could be helpful even if it isn’t ideal in every situation.