It's been a while since I've gotten any alerts to this thread, so figured Microsoft really doesn't care, which is the uttermost display of arrogance towards their customers, but guess that's just the way it is. I hate Gmail and guess I will continue to use Outlook despite my anger at MS for making this change, as it's still a lot better than Gmail, in my opinion.
I went to Settings to see if they had magically fixed the problem with Quick Actions, but of course they hadn't. However, I did stumble across something fairly easy that is the next best thing to having a Delete button back on the Left side of the email lists: Right Click the message you are hovering over and the drop down list has a Delete action. It's not quite as good of a solution than restoring the original location of the Delete quick action button, but it's better than moving your mouse all the way to the right and possibly losing sight of the particular message you want to delete. Also, since I have my Viewing Pane set to return to message list after deleting a message using the Delete button on the main toolbar, the next message becomes highlighted and ready to delete if I leave my mouse over the Delete button on the main toolbar at the top of the list, allowing me to easily delete consecutive messages quickly (but you do have to be careful and not go too fast!)