@NathanG - I think alliteration stands out more than assonance, in my opinion. In assonance the consonants can be different while the vowels sound the same, and while this creates a situation where the words may rhyme, the words themselves don’t have to follow each other necessarily.
Therefore I don’t think assonance is as easily detected upon first impression. But one thing that I’d like to point out is that sometimes in common speech, people stumble upon alliteration accidentally.
They may string together a sentence filled with words that begin with the “s” consonant, and so they have created alliteration without knowing it. I think it’s a little harder to create assonance by accident. At least, I haven’t come across many real life assonance examples.