E-cap does need a run in time (15 - 30 min) for the first time operation. The electrolyte flows and then comes to stable operation. Afterwards it works OK (unless you don't power it up for a year).
Other electronic components operate / comply with spec. from the beginning.
CRT / vacuum tube needs short run in time (5 - 10 min) for every power up due to optimized temperature and minor electron beam scattering (sorry, I am not too familiar with vacuum tube).
I am not against 煲機. And I don't mean 煲機 is meaningless. You may find the improvement after 煲機. And you are honest. Anything brings improvement is good to you.
I just mean that the improvement doesn't come from the product/hardware.