The benefit is risk reduction, not absolutism. You make it hard for lazy people with a bone to pick to find your old Tweets. You also increase the ambiguity (was this screenshot faked?) and costs for someone trying to uncover old Tweets at scale.
Yeah, just got to think about it as like a bike lock. It won't stop dedicated attackers or the government, but it stops opportunists and by putting it slightly above the rest of the low hanging fruit.
Today’s lazy person is tomorrow’s AI task that’s trivial and universally applied. When publishing to the net, think of your future.