Gutenberg InnerBlocks allowed types and reusable blocks

Yes, “why you can’t insert a reusable block inside your custom block when you’ve used alllowedBlocks?” This is what I am trying to get

This is because you haven’t allowed them:

allowedBlocks={['example/children']}

The list of allowed blocks does not include reusable blocks ( core/block ), so they are not allowed and cannot be inserted. Add core/block to the list to fix that.

Remember, a reusable block is a block of type core/block, its content belongs to another post entirely. If you say only example/children blocks are allowed, this does not mean a reusable block that contains example/children can be inserted, because a reusable block is of type core/block and has no inner blocks. You only see inner blocks in the editor because the UI is being helpful and showing you the blocks from the other post.