The Soul Sand Valley on Bedrock Edition doesn't use the updated spawn rates in Java 1.16, causing spawn rates well above anything a reasonable human being could survive. If you don't believe me, follow these steps on Bedrock Editon:
1. Go to the Nether.
2. Find yourself a Soul Sand Valley (use /locatebiome if you must)
3. Walk around a bit on any gamemode. You'll notice that there are too many skeletons and ghasts spawning way too frequently, and given that these two mobs have some of the worst AI compared to their Java counterparts, this biome is literally unplayable.
It doesn't sound too tough to fix, just use the new Spawn Budgets that Java does and you should be fine.
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Thank you for your report!
We're actually already tracking this issue at MCPE-65762, so I will resolve and link this ticket as a duplicate.
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