A computer program written with knowledge of a few dozen of the common special cases would pronounce >90% of English words correctly and be close on most of the rest, "cupboard" notwithstanding. Indeed, look at how well 80's-era speech to text did with this exact approach.
If English doesn't use a phonetic writing system, then what kind does it use? Ideographic? Syllabic?
In a phonetic language, you can pronounce a word just based on its written representation.
Just compare current and paste tense of read. It is spelled the same but pronounced differently.
You can argue it is an phonetically inconsistent language. However, you will find most of inconsistencies occur in the most frequently used words, making it hard for a beginner.
Even looking up the definition of "alphabetic" shows that that is often for phonetic languages. :D
If English was truly phonetic, to name a few examples again: the pronunciation of "are" would most likely be a prefix of "area", since the graphemes for "are" are present in "area"; "read" and "read" would be read the same, since the graphemes for "read" and "read" are identical; the words "freak", "steak", and "break" would end with the same phonemes, since the graphemes for "eak" suffix are identical... and so on.
I now suspect you have a fundamental misunderstanding of what a phoneme is.
What does the symbol “c” represent, if not two different phonemes?
The letters in the English script represent sounds. Do you disagree?