For the past 30 years, software companies have been benchmarking themselves against "IT spending." Global IT spending sits at roughly 1% of GDP—about $5 trillion. Every SaaS valuation model, TAM slide, and market analysis is built on this denominator. When investors see a deck claim "our TAM is $30B" or "we target X% of the IT budget," they automatically anchor to this framework. But vertical AI is rewriting one thing: what should actually be displaced is not the "software bu