Bugsy Siegel built tangible, visible assets—the Flamingo was a real estate monument that generated ongoing revenue streams and became a template for Vegas development. His $2M bet turned into a self-reinforcing property empire that other mobsters could see, touch, and replicate. But Siegel's wealth was tied to a single flagship asset; when he died, the Flamingo's value didn't evaporate, but his personal cut did. Lansky, conversely, never built one iconic property. His genius was architectural differently—he structured financial networks across casinos, loan-sharking operations, and money laundering channels that generated recurring percentage cuts without concentration risk.

The accounting gap reveals everything. Siegel's $400M sounds impressive until you realize it's mostly the Flamingo's appraised value attributed to him. Lansky's actual documented 1960s peak was $57M, which inflation calculators peg at $500M+ today—a real cash accumulation, not equity in a single property. Lansky took 2-5% cuts from dozens of operations across Miami, Cuba, and Las Vegas rather than betting his entire fortune on real estate appreciation. When casinos got raided, Lansky's money was already dispersed; when Siegel got murdered, one bullet eliminated the controlling shareholder.

The final irony: Lansky died "broke" by design, having spent decades moving money through Caribbean accounts, family trusts, and untraceable investments to evade seizure. His stated net worth was weaponized dishonesty—the perfect accountant's endgame. Siegel left his fortune visible enough that his widow and business partners could actually inherit it. Lansky's superior financial architecture meant his empire survived intact even after his death, while Siegel's died with him. In pure wealth accumulation measured by peak purchasing power, Lansky won by playing a longer, quieter game.