Here's why:
* "Best" has a unique vowel sound. It doesn't fit the typical vowel patterns of rhyming words.
* Rhyming requires similar vowel sounds. This makes finding a perfect rhyme very difficult.
However, you can find near rhymes or slant rhymes that share some sound similarities:
* Near rhymes: "blest," "quest," "test," "west," "crest"
* Slant rhymes: "rest," "chest," "guest"
These words don't sound exactly the same but share some phonetic elements, creating a subtle rhyming effect.