[Philip-J-Fry]

As far as I can remember the origins of Bedrock are the original console releases which couldn't ship a JVM. So a whole new codebase was developed, and ultimately it was more performant as it had to run on 7th gen consoles.

[ThatPlayer]

Console releases were done by a different studio originally, 4J Studios. Bedrock spawned from the mobile ports, and eventually replaced the console editions and had different features.