A child with speech delay and unclear speech is likely to find phonics tricky (as I know from being a voluntary helper at a club for people with learning difficulties for the past 32 years).
Many children learned to read very successfully with mainly 'look and say' (Ladybird Jane and John books), although they inevitably learned phonics as well when they began learning to write.
As adults, we all read by 'the look and say' method, not by decoding (except for the odd totally unfamiliar word). Many children learn that way too, although they no doubt cannot fail to notice that most consonant letters have stable sounds (b, ca/a/o, d, f, ga/o/u, h, j, k, l, m, n, p, qu, r, [s], t, v, w, x, z) and so use phonics as well.
Nobody learns to read English by phonics alone, because of phonic inconsistencies like 'on - only, once, other...through, tough, cough...
man - many, manger'.
It's not either or. And for some children 'look and say' works better for learning to read than pure phonics does.
Masha Bell