The problem will always be that that English has a lot more phonemes than it does letters, so a 1:1 mapping will never be possible. That said, I do think it would be a good idea to have a 1:1 correlation. Which is why everybody should just learn Esperanto instead.[1]
1: Joking.[2]
2: Well, mostly joking.
Rough: ro-uh-g
Not that hard. Not perfect either (hs are difficult to pronounce) but still helpful. It could easily become a game for children to talk to each other in this "secret language". And by doing so, they would be memorising the correct spelling of the words.
In German, this problem is solved by the convention that the written form exists to preserve the "correct" pronounciation. So, if you don't speak the word in the way it is written, you likely pronounced it wrong (yes, there exist situation where the pronounciation cannot fully be reconstructed from the written word; also newer loanwords tend to be written as in the original language; but these are rather exceptions).
Then there's also the etymology and handling of grammatical endings. Polish spelling would be more difficult without "rz" for example, despite its two sounds already existing elsewhere in the spelling system.
Spanish, for example: everything is spelled exactly the way it sounds, a sane design.
Or how about G? It makes one sound before I or E, another before A, O, UE, or UI, and yet another before UA.
Lots of folks think their language is simpler, but it's only because they can follow the rules so well they don't need to actually know them.
The fact that there are a few rules on how to pronounce combinations of letters (and even a few exceptions here and there) has nothing to do with the total mess that is English.
(the difference is aspirate vs. non-aspirate)