It's easy to wire a public API key into a basic chat interface. It's much harder to build software that reliably does a specific job — summarizing contracts a certain way, classifying support tickets against your internal taxonomy, drafting content in your brand's voice — without drifting, hallucinating, or breaking when the input looks slightly different than expected.
Off-the-shelf AI tools are built for the general case. When your workflow has specific rules, specific data formats, or needs to plug into software you already run, a generic tool usually can't flex far enough, and teams end up stitching together fragile no-code automations that break under real load.
There's also a model-selection problem: different tasks are genuinely better served by different models, and picking one and hard-coding it means re-engineering later when a better or cheaper option ships. Few businesses have the in-house expertise to evaluate that tradeoff correctly, let alone keep re-evaluating it as the field moves.