I work with a lot of curricula. There are degrees of specificity. Common core is, notably, absurdly specific, and dense. It’s the US at its best, which is to say its worst. Including the fact that CC hasn’t ever really been touched since. This is seldom how curricula in actual developed jurisdictions are built.

There are also degrees to which a teacher can ‘play it by ear’ in their classroom. This is informed by their ability to do so competently, and the freedom allowed by their school, school system, etc. The existence of a curricula, even in a public education context, doesn’t inherently disallow a teacher from attempting different teaching styles to get through to a kid, or changing what they focus on in order to teach to their students’ zone of proximal development.

Schools “adapting to metrics” is very much moreso informed by the undeniably reality that, with any sizeable group of kids, and realistic constants on resources, you quickly need to start doing “formative assessment”, and doing assessment well is really hard.

Above all though, schools adapt to metrics because it’s what’s demanded of them by their bosses. By that, I don’t mean ‘educational bureaucrats’, I mean…parents, taxpayers at large, etc. ‘Hold hands under a rainbow and nothing bad ever happens’ individualised education is simply very hard to monitor, it’s very hard to hold anyone to account. Stakeholders hate this. They want measurement. They want numbers. And numbers invite systems, and putting people into boxes. We get exactly what we deserve here. Nothing more and nothing less.