The difficulty settings of Bedrock Edition are not in parity with the Java edition, which overall makes the Bedrock Edition feel like a "kiddie" version of the original. This will prevent serious gamers from adoption the Bedrock Edition over the Java Edition.

Specifically

• Hostile mobs spawn less frequently everywhere
• Caves don't seem dangerous - no spooky sounds like in Java and finding a mob in a cave is more rare than finding a diamond (no challenge)
• Because mobs don't despawn, it's possible to live in an area w/o ever seeing a hostile mob due to ones that have spawned but are trapped in trees, caves, ponds, etc.
• Hostile mob attacks inflict hardly any damage on players 
• Hostile mobs can easily be knocked back and defeated with no weapon at all
• Mob hordes pose no threat as the player can spam full powered weapon attacks and take them all on at once

In general, the performance benefits of the Bedrock Edition are awesome, but the gameplay lacks the same challenge as the Java Edition. Maybe this is intended, but it seems that it could easily be fixed by adding additional difficulty settings.