Earlier quoted context omitted.
Literary French is quite phonetic, at least outside proper names. What are some examples where you feel that French writing is not in a one to one relation with pronunciation?
Granted, my experience with French is rather limited and the language could be pretty consistent internally. But there's lots of utter madness such as "beacoup" which is literally "buku". Sorry for being blunt but pronouncing 50% of the letters is extremely non phonetical. There's just no other way of putting it
Granted, the sibling comment lists quite a few exceptions to these rules, but it is still quite a regular language.
The system of silent consonants is quite useful in keeping the language have somewhat regular declensions/conjugations. If they were not preserved, it would seem that French conjugations are mad, inventing consonants out of thin air. For example, coup/coupee, meaning to cut/ cut (up), are pronounced ku/kupe. This would make it seem like the participle is adding -pe to the infinitive (and it would add -te or -ze or many others), when in fact the participle is almost always adding -e, which forces the consonant in the root to be pronounced, since French really hates hiatuses.
If anything, French phonetics are the real problem, aggressively dropping consonants of the end of words, but loathing hiatuses, sometimes even between words in literary contexts (where sometimes a 't' or 'z' sound is added between a word ending in a vowel and the next word beginning with a vowel, 'la liaison').