LLMs make it easier to build custom software, but that alone does not justify replacing systems that already work. The real issue is whether the time and money spent will create a lasting competitive advantage. Rebuilding standard systems like CRM or HR tools rarely clears that bar. Even if AI speeds up development, the payoff is small, and the opportunity cost is huge. Every hour spent recreating Salesforce or Workday is an hour not spent building the proprietary capabilities that actually move the business forward. That tradeoff is the real constraint. We saw this in the cloud era. Companies bought standard CRM and HR systems and focused their energy on the software that defined their customer experience and gave them an edge. AI lowers the barriers to custom development, but it does not change this basic logic. The smart strategy is to invest in the areas where innovation creates true differentiation and customer value, not in systems that are easy to rebuild but don't move the competitive needle.