Yes, I think you explained the cause of the observation.
As shown in the last GIF, the item can be referred by a block-reference.
In this way, I guess it is natural for the user to think that the item is a block. And by clicking this block-reference(linking to one item in the list), it should be the item(as a block), rather than the entire list highlighted. Only in this way, the logic within Obsidian looks self-consistent.
Considering that there is a todo list containing 100 items or sub-items. Now, I use 3-4 block-references pointing to some of the items, and I use the automatically generated block id. Noticing that in the preview mode, the block-id is invisible, in this situation, I guess it is impossible to locate the items that are refereed by these block-ids, in preview mode. And in this case, these block-references are almost useless.
I know that locating the correct items works fine in editing mode(that’s the reason why i used the wording almost above). And if you think this is the behavior that is expected, you may move this thread to the feature request area.
But if you also think this is the inconsistency in the logic introduced by using block-reference, I hope you can take this as a bug need to be fixed.