I do not work for Mojang so can't speak for why they actually switched to using UDP for the Bedrock versions; however, it is often better to use for real-time games as it doesn't get caught up on dropped packets or their sequential order but instead continues with the newest state of the game. When a packet is dropped with TCP it will essentially "pause" until it has successfully recovered the packet and then processes all backlogged packets in their "proper" order all at once. Without this restriction, you can process new packets as they come in and if there are occasional important packets you can build a system to detect, re-transmit, and process those at a later time instead should they go missing in transit. Due to Bedrock being available on mobile platforms (Android/iOS/Nintendo Switch) that are mobile/wireless-only (barring adapters), TCP's handling of dropped packets can make the experience much worse than a properly setup UDP system that can simply ignore them and process out of order.
There are other reasons to use either over the other as well so it just depends on what they were going for.
I do not work for Mojang so can't speak for why they actually switched to using UDP for the Bedrock versions; however, it is often better to use for real-time games as it doesn't get caught up on dropped packets or their sequential order but instead continues with the newest state of the game.
When a packet is dropped with TCP it will essentially "pause" until it has successfully recovered the packet and then processes all backlogged packets in their "proper" order all at once.
Without this restriction, you can process new packets as they come in and if there are occasional important packets you can build a system to detect, re-transmit, and process those at a later time instead should they go missing in transit.
Due to Bedrock being available on mobile platforms (Android/iOS/Nintendo Switch) that are mobile/wireless-only (barring adapters), TCP's handling of dropped packets can make the experience much worse than a properly setup UDP system that can simply ignore them and process out of order.
There are other reasons to use either over the other as well so it just depends on what they were going for.