I don't think Apple has any special tricks for input loop.
Some Android phones really have input lag, but it is not caused by CPU load. For example, on my phone, there is approximately 100-150 ms lag between tapping the screen and registering the touch. The lag is not caused by CPU load, but by slow touch sensor.
I don't think Apple has any smart code optimization tricks. Either they have a faster touch sensor or just some people believe that if something is made by Apple then it is of a better quality.
Here is a comparison of input lag in games in iOS and Android [1] and it shows similar results: 80 ms between a tap and reaction on screen.
Some Android phones really have input lag, but it is not caused by CPU load. For example, on my phone, there is approximately 100-150 ms lag between tapping the screen and registering the touch. The lag is not caused by CPU load, but by slow touch sensor.
I don't think Apple has any smart code optimization tricks. Either they have a faster touch sensor or just some people believe that if something is made by Apple then it is of a better quality.
Here is a comparison of input lag in games in iOS and Android [1] and it shows similar results: 80 ms between a tap and reaction on screen.
[1] https://blog.gamebench.net/touch-latency-benchmarks-iphone-x...