In 1955 Flesch concluded that English is 98% phonetic.
In that case anything else he says is of dubious validity.
I analysed the 7,000 most used English words, i.e. the words that an average 16-yr-old can be expected to have come across and would be able to use a fair proportion of.
Just over 2,000 of them pose some decoding problems, because some of their graphemes have more than one pronunciation (e.g. here, there, were; only, once, other; breathe, break, breakfast). The irregular sounds of some letters and letter strings are the main reason why becoming a fluent reader of English takes a relatively long time.
For spelling over 4,000 words are tricky like (tea, tree, he...go, slow, toe...) and ensures that learning to write English with moderate confidence takes around 10 years.
Many irregular spellings pose no decoding problems: lane - main, fly - high, stole - coal.
To most people this means that English spelling is highly irregular and that phonics can provide a good start with learning to read and write, but that the acquisition of both skills requires much word by word learning as well.
But to most phonics evangelists 'phonics' seems to mean all learning of reading and writing - not just the regular or dominant letter-to-sound correspondences. So in a lot of the discussions people are talking past each other, because they mean different things by the words they use. There is also a lot of ludicrous exaggeration when phonics evangelists decry mixed methods, as if children automatically pay no heed at all to any letters when learn to recognise common words by sight.
I have tried to bring some sanity and realism to the reading wars, but with little success.