That's a correct observation but it has to do with the design of the software. There's nothing anyone here can do about excluded features.
If this is something you believe would add value to the program please use Help> Feedback in the Excel menu bar to plead your case to the Microsoft development group. They do read & track responsible Feedback but don't expect a personal reply or any immediate changes to be implemented. Whether it gets added is based on a variety of factors such as volume of demand, priorities & return on investment as well as UI considerations... Software developers - including Microsoft - often have their hands tied due to Apple constraints.