The Abilty to download world's from With the same minecraft account

So my idea is to make it so that you may have the ability to download world's from other Devices With the same minecraft account or if you are Givin permission by your friends on minecraft and any changes made on the world is the same on both Devices . The Interface should Be a Collection of worlds on all of your devices with the thumbnail name and the ability to Search the names of the world's. And world's from Java or bedrock should not be cross Compatible the use of this feature is to save old world's when Devices are beings sold or when traveling  to play . Making these activities easier to do