Summary: Minecraft Bedrocks Mob Cap is 8 within a 20 block range instead of Javas 128 block range and is split between spawning areas allowing very slow mob farms and making hard mode in Bedrock easy mode in Java. Furthermore Minecraft Bedrocks Mob Cap isn't being rushed to be filled up within a player simulation distance.
Steps To Reproduce:
Step 1: Build a Mob Farm in Both Versions.
Step 2: Set Mode to Hard.
Step 3: Watch the Mobs Fall.

Observed Result: In Minecraft Bedrock you'll see that one mob has the ability to spawn at a time and doesn't immediately spawn the mobs like Java if the Mobs are able to making mob spawning more random and makes it impossible to make a efficient mob farm at a rate more than 10 mobs in 30 seconds vs Java 10-20 per second if you build a 2-3 platform for a Mob Farm. Furthermore you usually have to on Bedrock wait at least 5-10 seconds maybe more from the previous spawn to get more mobs to spawn.

Expected Result: Mob Spawning in Minecraft Bedrock should align more with 1.17 Java Mob Spawning Mechanics allowing efficient mob farms and instant mob spawning and with a higher mob cap to allow more mobs to spawn in a single area.

Minecraft Java Mob Farm: https://www.youtube.com/watch?v=tX_0mpyAoKU

Minecraft Bedrock Mob Farm: https://www.youtube.com/watch?v=ernu6IBHL9U