While enterprises might leverage AI to build custom in-house solutions, SMBs are highly resistant to the pain of switching core systems like point-of-sale. This inertia makes niche SaaS for SMBs more defensible against the immediate threat of AI-driven replacement.

The stickiest software is critical but inexpensive relative to a customer's overall budget, like payroll services. This 'Goldilocks zone' makes the software too small a cost for C-suite review, yet too embedded to easily replace, creating a powerful moat.

Established SaaS firms avoid AI-native products because they operate at lower gross margins (e.g., 40%) compared to traditional software (80%+). This parallels brick-and-mortar retail's fatal hesitation with e-commerce, creating an opportunity for AI-native startups to capture the market by embracing different unit economics.

Even if AI makes it easier to build competing software, incumbent SaaS giants retain customers due to immense switching costs. The operational disruption, retraining, and integration challenges of migrating a large organization create a powerful moat against new entrants.

Shopify President Harley Finkelstein argues that while AI will rewrite user interfaces, it won't replace core transaction infrastructure. Shopify's defensibility comes from its comprehensive back-office system managing inventory, taxes, payments, and fraud, which is far harder to replicate than a simple storefront.

SaaS pricing has always been determined by the value it delivers to customers, not its cost to build. While AI makes development cheaper and faster, it doesn't fundamentally change the value a product provides. Therefore, companies that solve important problems will maintain their pricing power and high margins.

AI doesn't kill all software; it bifurcates the market. Companies with strong moats like distribution, proprietary data, and enterprise lock-in will thrive by integrating AI. However, companies whose only advantage was their software code will be wiped out as AI makes the code itself a commodity. The moat is no longer the software.

AI is not killing B2B SaaS, but it is fundamentally changing the competitive landscape by making software easier to build. This commoditizes core features, forcing existing SaaS companies to develop unique, defensible moats beyond just code to protect themselves against a new wave of competitors who can quickly "vibe code" similar solutions.

Alex Rubalcava argues that businesses won't replace software integral to their operations—systems of record or platforms touching money, regulation, or physical assets. The high cost and risk of failure create a strong moat against AI-driven replacements, protecting companies like Shopify and Viva.