1. Capitano is very handsome and I believe he will grant benifits to both players (game wise) and devs (buisness wise)
2. I cried after he died and I, along with many capitano fans, would like to be able to play genshin with our no.1 harbinger.
3. I believe his character kit (I think that's what it is called) would be absolutely amazing to play
4. If capitano is playable many genshin fans (definitely capitano fans) will be overjoyed 

those are many of the reasons capitano should be made into a playable 5 star cryo sword user. In all truth I don't believe I needed to write any of this out, I truly believe that there is no need to argue this.

Edit: I'm making this because Google keeps telling me he will and won't be playable and I want to try make sure he is playable