Another reason is that compared with the open source Android system, Apple's closed system does not have so many mute modes. However, android users can set mute in many ways, such as reversing the phone or customizing mute. This can be done, but the limitations of Apple's mobile phone are very strong. This is why Apple phones must have a specific mute button, while Android phones have no such consideration at all. That's why you don't need a mute button next to an Android phone.
But now Apple's mobile phone is gradually changing, and many iphone users have also said that Apple's buttons are inconvenient now. It is often accidental, so now Apple is also in the process of gradual progress and improvement. Most importantly, the buttons on Apple's mobile phone are not very useful for many people now.
Summarize; With the continuous development and improvement of the mobile phone system, Apple's ios and android learn from each other, and the system will become more and more similar in many functions. As far as the current or future mobile phone design is concerned, the setting of mute button actually increases the difficulty of making a thin, waterproof and scalding-proof full-screen mobile phone. So Apple may also delete the physical mute button on the iPhone soon.