In previous versions spectator mode was accessible by editing the player data "PlayerGameMode: 3" which would allow flying and clipping through blocks. I dont know if this was a "fix" or some kind of way to stop people from using that game mode but it is no longer working. Bedrock needs spectator mode just like Java
Thank you for your report!
However, this issue has been closed.
Going forward we're going to be tracking parity issues and feature requests on the Minecraft Feedback Site, and we'll be tracking bugs here at bugs.mojang.com.
We're already working on achieving parity across versions where possible, and we're very keen to hear your requests or suggestions, so we'd encourage you to make a post at https://feedback.minecraft.net, or upvote an existing topic there.
https://feedback.minecraft.net/hc/en-us/community/posts/360009225992--Java-Parity-Spectator-and-Hardcore-game-modes-to-Bedrock-Edition
If you're not sure whether your issue is a parity request or a bug, hopefully this article will help explain further: Parity Request Guide
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