From How languages compare with the number of different syllables from all words?, considering the 20,000 most frequent words in each language, Mandarin Chinese has 1274 different syllables (see also 3 and 4). Compared to other languages, such as English with 6949 different syllables or Spanish with 2778 syllables, it has a small number of different syllables.
This might be the reason why Chinese has many characters repeating phonemes and why I wondered Does Chinese require more context to avoid ambiguities than English?
What are the possible historical / linguistic reasons behind this? Is there some relationship with the writing system, as Mandarin Chinese uses characters?