> the approach where "agents" accomplish things by using the browser/desktop always seemed off to me

It's certainly a much more difficult approach, but it scales so much better. There's such a long-tail of small websites and apps that people will want to integrate with. There's no way OpenAI is going to negotiate a partnership/integration with <legacy business software X>, let alone internal software at medium to large size corporations. If OpenAI (or Anthropic) can solve the general problem, "do arbitrary work task at computer", the size of the prize is enormous.