Many founders and engineers complain about Salesforce (bloated, expensive CRM), SAP (complex, costly ERP), and ServiceNow (overpriced ITSM). X discussions and reviews show strong demand for modern alternatives, yet no clear dominant replacer has emerged by 2026. Which of these three feels most vulnerable to a startup-built, AI-native replacement? Where is the biggest opportunity for YC/mid-size focused disruptors?