The main thing that people need to actually type for is suggesting items. This can be fixed if Riot would allow players to link items from the shop into chat.
Most English speakers abbreviate Infinity Edge as IE. Now, that doesn't make sense in French, where Infinity Edge would be called "Lame d'infini" and be abbreviated LI. In Spanish it's "Borde infinito" and abbreviated BI. So if you're telling your ADC to build an Infinity Edge or to rush it (or if they're Ezreal, not to build it), they can't figure out what item that is if you just say IE (or if they don't speak English, even if you type out Infinity Edge they don't understand).
But if we had a link, the English speaker with his English client could link Infinity Edge into chat, and it would come up as "Lame d'infini" to the French speaker or "Borde infinito" to the Spanish speaker. You could just shift click an item from your inventory or the shop to link it into chat and the issue would be solved.