A boy I once taught, writing about his struggles with spelling, wrote
I think English is a stupid langwig
Two learned American professors of language, however, called it
a near-optimal system
Who is right? Most people I know would side with the boy. Again and again people complain that the letters don't always stand for the sounds they should stand for. They don't and they couldn't be expected to because there are only 26 letters and about 44 sounds in English; the number varies according to how people speak.
One reason for the problem is simply that hardly any of us have any idea how the system works. English is a mixed language, so it is not surprising that it has a mixed spelling system. Some spellings depend on sound, but a lot of others don't and because of our seafaring history and contacts overseas, we have also brought in huge numbers of words straight from other languages, often (but not always!) adopting the spelling of the country they came from. It is sometimes easier to read words if they are not phonetically regular. Finally English has a huge number of words (like write and right) which sound the same but are written differently because they mean something different. "One Spelling One Meaning" is a better slogan than "One Letter One Sound".
So there is undoubtedly more work attached to learning English spelling than there is for Spanish, say, or Finnish, which have almost entirely regular phonetic spelling. But we have to learn it because it isn't at all likely to change. People are always agitating for reform but no-one has ever found a system yet which has caught on. Think of the difficulties. A lot of powerful people would have to agree on a new system and printers all over the world, since English is now a world language, would have to change all their machines. Neither of these things is at all likely to happen.
So it is hard to learn but we make it much harder by not understanding it and by not understanding how children's spelling develops. This causes us to mislead children, albeit with the best intentions. And some of that happens in the teaching. Many children learn to be poor spellers in their classrooms.