The "micro framework" phase happens when that "macro" framework fails to deliver something. It happens way less often than a team picking a big estabilished tool.
However, the sizes never mattered. That is likely what causes the confusion in the first place ("it's large so it must have lots of things I want", "it's small so it must be easy to understand").
The real red herring is focusing on the size (or LOC, or any vague metric) instead of other more relevant architectural properties.
However, for a beginner, specially if said beginner never worked in a larger company with resources to produce an internal framework, they might think you're referring to Flask or something like that (btw Flask-style microframework use can go very wrong but it's another completely different issue).
That's why I'm being nitpicky. The people who'll get the post are likely already experienced enough to evaluate those frameworks themselves.
That is also true for "macro" frameworks.
> Wraps around the company/org-shared tech stack or framework
That is often also true for "macro" frameworks.
> Creators claim that the framework "magically" solves many problems, and push more people to use it
That is often also true for "macro" frameworks.
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It is not clear from the reader's perspective what actually characterizes a "micro" framework. It's also not clear why the size is the issue here, when all complaints seems to be about design or quality.
Is googletest a micro or macro framework? Is google/zx a micro or a macro framework? Give us some clarifying examples. Actual things people can look for, not internal unknowable projects. There must be some exceptions too (silver bullet rules don't exist), mention them.
Also, rethink the title. Maybe "makeshift frameworks" is better terminology, as it more accurately reflects the problem that is described in the content.