So basically English spelling is trapped in a local minimum. An small change will make spelling closer to some dialect, and further from most other dialects. The current situation is suboptimal for everyone, but at least it's a Nash equilibrium.
Another easy example is just fixing "island". The <s> was never pronounced. Medieval scribes put it there because they incorrectly guessed that the word was related to Latin "insula".
The real low-hanging fruit is getting the British to give up on those spellings that follow a dead branch of French ;-)