The previews in the dock only activate when the cursor is directly on top of the icon. However, my muscle memory on the dock is based on bringing the curser all the way to the bottom of the screen so that it is below the icon. In the dock, this action highlights the app and makes it clickable. However, previews do not appear when doing this. I've added a screenshot below.
This would be really awesome to have. As when we have our dock below or to the right/left, we tend to just throw our mouse pointer, and we do not see the preview as it's "below" the dock...
The previews in the dock only activate when the cursor is directly on top of the icon. However, my muscle memory on the dock is based on bringing the curser all the way to the bottom of the screen so that it is below the icon. In the dock, this action highlights the app and makes it clickable. However, previews do not appear when doing this. I've added a screenshot below.