Why did you introduce fluid

The introduction of "Liquid Glass" at WWDC was a significant step in evolving the look and feel of Apple's software. Liquid Glass delivers a unified design language across all platforms, seamlessly blending hardware and software. It introduces a more fluid and dynamic interaction experience, bringing a striking new look to every part of the interface. This new material is designed to be adaptive, responding to both the fluidity of touch and the dynamism of modern apps, making the experience of apps feel more organic, immersive, and fluid.

Liquid Glass combines the optical qualities of glass with responsive fluidity, designed to refract content from below, reflect light from around it, and have responsive lensing along its edges. This creates a new level of depth and vitality, making the interface feel alive and directly connected to the physical world and device input. It also adapts automatically across different contexts and platforms, ensuring legibility and maintaining clear separation from the content layer.

For more details, you can refer to the session Meet Liquid Glass (19:03) where these concepts are discussed in depth.