I think that there should be more ways to chat, because the chat is fine in some ways, but in other scenarios it is really annoying. I have come up with 4 different chat ideas that should be changeable using /gamerule ChatOption option
1. Regular chat. The same chat as we have now.
2. Speech bubbles. A little bubble above your head shows what you're saying. It is only visible when you are within 5-7 blocks away from someone, and not visible through blocks. This would reduce spam a lot on servers. I am building a minecraft school as some kind of RPG map, and this would make the huddles at spleef matches more private. I know that this is from roblox, but it could be very useful.
3. Combined chat. The chat messages on the bottom, along with the speech bubbles.
4. No chat. Nobody can chat. The only way to communicate is to write messages in books and throw them at each other
I think the regular chat we have now is good enough.
I don't know what it is, but I don't think speech bubbles fit in to Minecraft, and the whisper plugin already establishes team speaking. I personally don't think it'd be useful enough to incorporate speak bubbles into the game.
EDIT:: Agree with below, WAAAAAAY too much lag in server spawn hub areas.