Floor vs Ceiling: Different Models for Different Jobs

I talk a lot about the floor versus the ceiling when it comes to LLMs and agents. The ceiling is the maximum capability when you push these models to the edge of what they can do: complex architectures, novel scientific problems, anything that requires real reasoning. The floor is the everyday stuff, the entry-level human tasks that just need to get done reliably.
For customer service, you want floor models. Cheap, fast, stable. For cutting-edge research or gnarly architectural decisions, you want ceiling models. Expensive, slow, but actually smart.
What I've realized lately is that coding agent workflows should be using both. And most of them aren't.