Why it happens
Why statements from the same city start looking alike

The short answer
Because a small number of templates serve a large number of applicants. When one office writes hundreds of statements a season from the same skeleton, admissions readers see the same openings, the same paragraph order and the same phrases arriving from the same city year after year. The cost falls on the good applicant whose real record is hidden inside a familiar shape.
How convergence happens without anyone intending it
A template exists because it works often enough. It is filled in at volume, under deadline, by people writing about applicants they have spoken to briefly. The result is not dishonest; it is generic, which is a different failure and a more expensive one.
Kerala sends a large, concentrated cohort to a small set of destinations. That concentration is exactly the condition under which a reader starts recognising patterns.
What a reader actually notices
The opening. "From a young age I have been fascinated by" and its variants are the best-known, but the tell is broader: any first line about the importance of the field rather than something that happened to you.
The fit paragraph. Reputation, ranking and world-class faculty appear in template statements because they can be written without research. A named paper or module cannot.
The shape. Identical proportions across many applications from one place is itself a signal, even when every sentence differs.
What actually breaks the pattern
Specifics that could not have been written about anyone else: a result and the number attached to it, a failure and what you changed, a paper you disagreed with. Our method for building that starts from evidence rather than from a structure.
This is also the practical argument for working from documents rather than a questionnaire, which is what separates the provider types.
Related questions
Do universities blacklist consultancy-written SOPs?
Not formally, and admissions offices rarely say anything publicly. What happens is quieter: a reader who recognises a familiar template reads the rest with lower expectations, and a borderline application loses the benefit of the doubt it might otherwise have had.