Since its inception, Apple has faced numerous complaints about its refusal to permit third-party watch faces. Now, six years and seven generations later, with millions of Apple Watches sold, Apple remains unwavering in its policy. However, the authoritarianism in this matter is deemed necessary as it helps Apple ensure the following:1. Aesthetic appeal
At first listen, it may seem illogical, but it's incredibly persuasive: the Apple Watch, beyond its smart features, remains a timepiece, still requiring a sense of fashion atop it, and the watch face is where that is most evident because it's the most frequently seen aspect (with the largest area). Hence, Apple's desire to control the aesthetics on the watch face of users' Apple Watches is understandable.
To ensure aesthetic appeal while still satisfying users, Apple has curated a vast repository of watch faces with a plethora of different styles.
This exclusivity also facilitates Apple's collaboration with fashion brands in releasing exclusive watch faces, similar to their partnership with Hermes. If you spot someone wearing an Apple Watch displaying the Hermes name on the watch face, it's indeed the genuine Hermes edition, not a counterfeit.2. Practicality
There are numerous watch faces on the Apple Watch that are not only aesthetically pleasing but also practical. They display a plethora of real-time information, aiding users in staying updated and in control of the information they desire.
To achieve this, the watch faces must utilize various hardware components inside the watch (such as the gyroscope, altimeter sensor, noise sensor, etc.), not just simply display the time.
While third parties may not create watch faces, they can still showcase their intelligence on the Apple Watch face in areas permitted by Apple (referred to as complications). This enables users to observe highly personalized information while still ensuring the stability of the watch face.3. Stability
By controlling end-to-end processes from hardware production to software development, Apple's watch faces are always guaranteed to operate smoothly and reliably. Minimizing compatibility issues (such as freezing, lagging, battery drain, etc.) will prevent any deterioration in the watch experience.
I've previously installed third-party watch faces from other brands, and excessive battery consumption is the most common issue. Third-party watch faces often utilize various hardware components continuously without balancing battery resources, leading to undesirable battery drainage.