From a philosophical standpoint, Mojang likes the idea of baby dolphins and would have added them if it were possible. From a technical, this-is-how-the-game-works standpoint, because dolphins were given a special functionality to play with items and lead players to hidden treasure there's no space in their concept to allow for taming, breeding, or riding--all of the ways that you would interact with the dolphin to engage in those activities is already occupied by existing functionality.
Mojang does not want to give up the unique features that dolphins express in Minecraft, so this idea is a dead idea that mojang has specifically asked us to stop suggesting (you can see the full list of all dead ideas on the feedback site). They are not going to implement it, period.
you will be able to ride dolphins by feed them with tropical fish. also there can be drowns that ride on dolphins.
baby dolphins will be spawn after feed 2 dolphins with tropical fish.
From a philosophical standpoint, Mojang likes the idea of baby dolphins and would have added them if it were possible. From a technical, this-is-how-the-game-works standpoint, because dolphins were given a special functionality to play with items and lead players to hidden treasure there's no space in their concept to allow for taming, breeding, or riding--all of the ways that you would interact with the dolphin to engage in those activities is already occupied by existing functionality.
Mojang does not want to give up the unique features that dolphins express in Minecraft, so this idea is a dead idea that mojang has specifically asked us to stop suggesting (you can see the full list of all dead ideas on the feedback site). They are not going to implement it, period.