There are two main problems with English orthography.

Firstly, that various spelling systems have been adopted over the centuries, without ever superceding their predecessors, and secondly, that English pronunciation has changed dramatically since it became (more or less) standardised.

As a result, although night may still be pronounced as written (mainly in Scotland), the gh has vanished completely in most the Anglophone world, while the i has turned into ai.

Change, of course continues, most noticably in London, where are white and wait are homophones, though still with different initial consonants and vowels in much of the rest of the English speaking world. In fact, one of the biggest problems with spelling reform is that it will never do more than reflect a snapshot of one local dialect at a limited point in time, unless we take a similar attitude to Welsh and do away with standardised spelling. Is "I am" in Welsh "dach i" "dech i" "dych i" or "ydych i"? (rhetorical question). The fact that there was no universal standard orthography in the 16th century means that for a linguist, the variant spelling used by Mary Stuart and Elizabeth Tudor in their letters can tell us a lot about the development of the different varieties of English at that time.