The layers of the stack don't move. Regulation doesn't retreat, encoded knowledge doesn't decay, first-party data keeps compounding. What moves is everything outside them: how much AI can already do on its own, and therefore how many customers still have to buy.
So picture the market as a pyramid. The most demanding customers sit at the narrow top; the least demanding at the wide base. Now draw a waterline across it. Below the line, the need collapses: AI does the job directly and nobody has to buy anything. Above it, the complexity still justifies buying.
That's the erosion people expect. There's a second one, running the other way. The most demanding customers are also usually the largest and the most expert: some understand the domain better than any vendor serving them. They were never buying knowledge, only the capacity to turn it into software, and that capacity is what AI hands them. They don't leave because their needs got simple. They leave because they can finally have exactly what they want instead of a product built for everyone.
Neither boundary is fixed. AI lifts the waterline from below and lowers the cost of building from above. The layers themselves don't weaken. The set of customers they protect narrows from both ends, and what's left is the middle: demanding enough to need you, not sovereign enough to replace you.
“The stack gives you altitude. The pyramid gives you rate. You need both to answer the only question an owner has: how many years are left, and which layer goes first.”
Chegg: The base was the whole market
Chegg's customers sat at the base of its own pyramid: students with routine questions, the widest and least demanding layer in that market. The waterline didn't cut through Chegg's category. It rose past the whole thing in one step.
Quentic: Clear of both lines
Quentic's customers sat in the middle: industrial operators tracking incidents and audits across multiple sites and jurisdictions, where being wrong means fines, shutdowns, or someone getting hurt. Demanding enough that AI alone wouldn't do it, and none of them held the cross-jurisdiction regulatory picture Quentic had encoded. That's the zone that holds.