I think the other component of the moat is that their OS/GPU stack is power-optimized for this effect in hardware, which generic solutions for generic hardware will have trouble matching - even a lower fidelity replication’s power drain could be an order of magnitude higher as a result.

True, innovation is much easier when you have full control over the hardware. My project would have taken a fifth of the time if I were only targeting Safari on Apple devices. But I trust that clever engineers and developers will keep finding ways to optimize effects for other platforms and devices.