In the first attached screenshot, as long as there are no external vibrations, the long delay repeater will never depower.

However, when vibrations are sent from further away than the thing triggering the sculk sensor to clock, as shown in the second screenshot, you can see the vibration being sent, and the delay from the location of the vibration occurs before the sculk sensor powers. 

Note that in the second setup, the piston powers after the trapdoor in the same tick, which is intentional to make the trapdoor trigger the sculk sensor reliably, but it can be done without.

This is an issue because it doesn't fit with the concept of the vibrations creating delay as they travel.