Users can now prompt an AI to build a custom version of a SaaS tool, tailored to their exact needs. This marks a shift towards personal, disposable software, which increases software's abundance while simultaneously eroding the moats of traditional SaaS businesses.

Enterprise sales for SaaS companies are becoming harder because AI has dramatically lowered the cost and time required for customers to build solutions in-house. This gives customers a credible alternative during renewal negotiations, eroding the vendor's pricing power and leverage.

Enterprises no longer need to buy expensive SaaS products for tasks like customer feedback. They can now spin up custom AI agents internally, making it harder for SaaS companies to acquire new customers and leading to higher-than-modeled churn. This poses a fundamental threat to the SaaS business model.

The traditional moat of enterprise software—high switching costs—is eroding. For the first time, customers can harness powerful AI models to custom-build their own alternatives, particularly for ancillary applications. This threatens the growth models of incumbent SaaS companies that rely on upselling.

Companies are now rejecting expensive SaaS contracts because their internal teams can build equivalent custom solutions in days using AI coding tools. This trend signals a fundamental threat to the traditional SaaS business model, as the 'build vs. buy' calculation has dramatically shifted.

AI tools enable users to create bespoke applications tailored to their needs. This shift towards personalized software challenges the one-size-fits-all SaaS model, potentially rendering many subscription products obsolete and causing market underperformance, as seen in the Morgan Stanley SAS index.

For decades, buying generalized SaaS was more efficient than building custom software. AI coding agents reverse this. Now, companies can build hyper-specific, more effective tools internally for less cost than a bloated SaaS subscription, because they only need to solve their unique problem.

The narrative that AI will kill SaaS is flawed. While anyone can now use AI to build custom tools, established companies retain value through brand and distribution. The real impact is deflationary: SaaS companies must lower prices to compete with the new "build-it-myself" alternative, compressing margins across the industry.

SaaS growth relies on upselling features and adding seats. AI challenges this by enabling customers to build their own integrations that were once expensive upsells. Furthermore, if AI keeps team sizes static, the "expand" motion of selling more seats vanishes.