Countless hours are wasted each year trying to teach people in this country the difference between the words "to", "too", and "two". However, it is always contextually clear what a person means when they verbally speak the word. Changing these words to a single written word would make it so writing is just like speaking.
Additionally, changing the word to the numeric "2" will indicate to people that they are using the new word. It also has the benefit of being 1 character long which is easier to type or write.
This will save wasted time discussing the issue, decrease the amount of time spent typing the word(s), and bring our country up to speed with the digital times.