It’s scarcely a reach to suggest that these men, each in their own ways, were desperately seeking external validation – proof of their own value and worthiness: more money, power, achievement, adulation or desirability.
It’s no different than using any drug. When it stops working – as a sedative or as a stimulant — the impulse is to increase the dose. And what’s the symptom they’re all seeking to treat? No one can say with certainty, but I strongly suspect it’s a vast feeling of inner emptiness.