The problem with "one spelling the way it is said" is that (1) pronunciation varies among native speakers even within the same country or region. (So, at best, you'd have to pick a winner or just count them all as different languages with their own spellings.) (2) Pronunciation drifts over time (and I'm not sure an official spelling and pronunciation could stop it).

The other reason is that there are many countries that speak English, and the largest and most powerful one is too politically dysfunctional to ever agree on something that would be this controversial.