Does this mean 'focus' was bad advice?

No. It was accurate advice given the cost structure that prevailed. Building a second surface was genuinely too expensive for most small teams. The advice was correct about the conclusion but silent about the reason, which matters now because the reason changed.

What exactly did AI make cheaper?

The build cost of product surfaces specifically: screens, forms, empty states, responsive behavior, test scaffolding, and documentation. It did not cheapen the judgment about what to build, the taste that shapes it, or the ongoing maintenance of keeping multiple surfaces in sync with a changing engine.

Does this apply to physical businesses too?

Less directly. In physical businesses, the surface layer is often human: trained staff, scheduled people, printed materials. Those costs have not dropped much. The argument applies most strongly where the product surface is made of code rather than people.

Is this just the classic 'multi-brand strategy' repackaged?

The multi-brand strategy itself is old. What is new is the cost threshold at which a solo builder or tiny team can execute it. The architecture was always possible. The budget was not, and that budget constraint is what gave 'pick one market' its force as universal advice.

"Pick One Market" Was a Price, Not a Principle

The advice to pick one market and serve it well was never wrong. But it was never purely strategic either. It was downstream of a price: the cost of building, maintaining, and supporting a second product surface for a second audience. When a price stays high for long enough, it stops looking like a price and starts looking like wisdom.

How Cost Became Principle

Serving a second audience properly means building a second surface. A surface is never just screens. It is design, build, tests, documentation, onboarding copy, support load, and maintenance for as long as the product stays alive. For a solo founder or a team of three, that cost was prohibitive. You multiply it by every audience you were ever tempted by, and the math closes the door before strategy even enters the conversation.

This is why "focus" arrived dressed as a virtue: discipline, maturity, the sign you had finally grown up as a founder. The framing obscured the real mechanism. You did not choose one market because one market was philosophically correct. You could only afford one.

The Courier Service Proof

Before software, this same dynamic played out in physical businesses. One courier operation ran two brands: one premium service selling a promise rather than a price, and a second tier below it. Same couriers, same dispatch software, same logistics. One engine, two names on the paperwork. Above that shared line, the brands shared almost nothing: different pricing, different sales conversations, different tone when a customer called at eight in the morning about a missing package.

A third brand was visible and viable in theory. But the surface layer in logistics is human: staff trained into a different voice, materials written a third time, people scheduled. There was no third of the founder. Two was where it stopped, because the surface cost was denominated in people.

What Changed

In software, the product layer is mostly screens, copy, tests, and documentation. AI collapsed the build cost of that layer specifically. Not the thinking, not the judgment about what deserves to exist, and not the taste. Just the surface. The tenth surface now costs something close to what the second one costs. That is the number that forced the original choice, and that number moved.

This does not make the advice obsolete. It makes the advice situational again, rather than universal. The question is no longer "can you afford a second product?" but "should you build one, and can you keep it honest over time?" The constraint shifted from budget to discipline.