Minecraft Java Edition version 1.14 tweaked the behavior of TNT so that it dropped all blocks that were broken in the explosion. Bedrock however still uses the old functionality where the TNT will drop SOME of the blocks that were broken. This is important because it allows multiple TNT-based farms to function properly and efficiently, and allows for some tutorials made for the Java edition to be followed on Bedrock, which I would say is the end goal for the whole parity discussion.