This bug has already been reported in 2020 (MCPE-102625) but it still hasen't been fixed after 3 years and the author of MCPE-102625 isn't responding, so I have creatde a new ticket to speed up the fixing.
The problem: "minecraft:on_player_destroyed" does not work when the player destroys the block in creative mode.
Steps to Reproduce:
1. Create a cutsom block with a "minecraft:on_player_destroyed" event (addon provided below)
2. Set gamemode to creative
3. Place block and destroy it
Observed Results:
when block gets destroyed in survival mode the corresponding event will be triggerd
when block gets destroyed in creative mode the corresponding event will not be triggerd
video: https://youtu.be/xwivVEZ7mLg
Expected Results:
block event should be triggered no matter what gamemode the player has who destroys the block
Linked issues
Attachments
Comments 5

It seems to me that having this trigger in creative mode would be a much greater inconvenience than having it not trigger. Suppose you were building something from blocks set to explode when broken by players. Then, if you made a mistake and needed to remove a block, it could result in a chain reaction that destroys all of your work. Having the component only work for players in survival mode gives you the ability to control whether it should trigger because you can change your game mode. Making it always trigger regardless of game mode would remove that control.
Thank you for your report!
However, this issue has been temporarily closed as Awaiting Response.
Could you please attach an example addon showcasing the issue?
This ticket will automatically reopen when you reply.
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@GoldenHelmet Yes, but people could just use /setblock to replace the block with air.
Or Mojang could add a query which checks for the players gamemode (e.g. !q.has_gamemode('creative')) which could then be added as a condition for the event - in this case, if the player is NOT in creative mode this event will be triggered. Same results - everyone is happy... but I don't think so that this will be added very soon.
The setblock solution solves the problem for everyone.
@GoldenHelmet I fail to see the inconvenience of a block doing what it's supposed to do when broken while in creative.
Let's say you have a block meant to explode so you place it to remove more blocks and it doesn't work. The player would be confused by this behavior and think the addon is broken.
Some blocks also use this event to figure out what items to drop, for storage-related reasons, like custom jukeboxes.