This seems suspicious to me, like you're playing a game with words that I'm not able to precisely identify.
Isn't this conflating objective reality (which we can only theorize about) with objective knowledge about reality (which can improve over time but never be perfect)?
The theory of the luminiferous aether "caused" the Michelson-Morley experiment, the outcome of which was inconsistent with the luminiferous aether actually existing. The theory of atoms "caused" many experiments, the outcome of which was consistent with atoms actually existing.
What causes theories to exist? Conjecture and criticism motivated by logical and empirical problems. The problems are "caused" by objective reality, of which atoms are one part (at a certain level of explanation, anyway).
An account of the development of scientific knowledge should explain the development of these problems, the conjectured solutions, and criticism made to them, and why the current explanations are the best available in light of this history. At no point do we need to claim that the current explanations are the best possible, but they are still objective knowledge.
This is starting to sound like history or sociology. The next step comes when you notice that the "the theory of" keys on your typewriter are getting excessively worn, and adopt a convention that any reference to "atoms" actually means "the atomic theory of matter".
There's a convention in scientific reasoning, that I'm not allowed to say, "Einstein believed that spacetime is curved", although in fact he did. This is a safety measure: if we forbid people from saying that, we don't lose much, but we avoid some common ways of fooling ourselves.
Sociologists are coming from the other side. They are allowed to say, "because Einstein believed that spacetime is curved", but they can't say "... because spacetime is curved." The readers know that spacetime is curved, and it's tempting for them to forget they are not the people whose actions they want to explain, and those people acted as if spacetime were flat. Perhaps they noticed things that were inconsistent with spacetime being flat. They never directly noticed that spacetime was curved: if it were possible to notice that directly, no one would ever have believed otherwise.
Isn't this conflating objective reality (which we can only theorize about) with objective knowledge about reality (which can improve over time but never be perfect)?
The theory of the luminiferous aether "caused" the Michelson-Morley experiment, the outcome of which was inconsistent with the luminiferous aether actually existing. The theory of atoms "caused" many experiments, the outcome of which was consistent with atoms actually existing.
What causes theories to exist? Conjecture and criticism motivated by logical and empirical problems. The problems are "caused" by objective reality, of which atoms are one part (at a certain level of explanation, anyway).
An account of the development of scientific knowledge should explain the development of these problems, the conjectured solutions, and criticism made to them, and why the current explanations are the best available in light of this history. At no point do we need to claim that the current explanations are the best possible, but they are still objective knowledge.