Non-repetition: a linguistic universal
There is a long tradition for the use of the word "dissimilation" to indicate the phenomenon of non-repetition in language. I prefer the term non-repetition which is not burdened by the classic discussion from Pott to Grammont to Togeby, which generally has treated language history and dissimilation in single words, while I will take a broader perspective, including a purely synchronous view and a statistical method.
In my opinion, it is not yet widely recognized that the tendency to non-repetition is a linguistic universal; that is to say that it is part of the basic structure of language, present in every kind of language, dialect or sociolect, in all historical periods and at all stylistic levels, and it is found at the phonetic and at the morphological level (including word formation) as well as at the syntactic, semantic or pragmatic levels.
It is characteristic of this general tendency that it always exerts its influence, and when we find cases where this influence does not seem to have any effect, the reason is that another linguistic feature, of a more specific nature, has been stronger than the tendency towards non-repetition.
In numerous descriptions of the grammar of a single language, or in more general studies on linguistic subjects, it is quite common that the concept of non-repetition - and even the concept of repetition - either is not mentioned or is mentioned in passing in some context, e.g. as "explanation" of a deviant historical development of a word (an exception), but without going into the question, almost as if you have a kind of shyness towards the subject. This is perhaps due to the fact that the traditional debate on "dissimilation" from Grammont to Togeby has made it a question of faith if one considers "dissimilation" or non-repetition as a regular and general phenomenon, or as a "sporadic" and randomly occurring sound change. I believe that the statistical studies on this site will demonstrate that the tendency to avoid unintended repetition is a completely general phenomenon, which, incidentally, goes beyond the world of language and affects human behaviour in general.