Hi accounts187,
The new home for Create (+) button has been moved to a new location (left bar) and renamed as + New. This changed to better position the button closer to where the rest of your work gets done. Thus, bringing it back isn't possible.
You can read our blog about "What’s new in QuickBooks Online" for more information.
Please don't hesitate to reach out anytime if you have more questions. We're always here to help.