Yes, it's not really FFXIV related, but I was just curious and figured that my best resource of people that I already know who might happen to know some Japanese would be here. If you don't know the answer to the question, my apologies for taking up your time.
Anyway, while I understand the difference between わ and は, and when to use は (for pronouns) vs when to use わ (as part of a word), I was wondering: Why is there a need for two characters for wa? For example "わたしは..." where wa is used twice. As I said, I understand that は is the particle pointer and わ is not, but why the need for two characters, as opposed to "はたしは" or "わたしわ"?