What happens with a PSU over time?

Hello GURU's,



I have been looking over a lot of reviews from jonny & crew and I have to say that they do an amazing job!



I do how-ever have the question about what happens with a PSU over time? I often hear people say; "A PSU loses wattage over time, so I should buy a bigger wattage PSU than I need."



I don't think is correct? I believe that the only thing that does happen over time is that the efficiency gets slightly worse. So if a system would pull 500W from the wall at a certain load, it would pull 510W in let's say 3 years time (I don't know anything!) if you would put the system under the exact same load.



Would love to hear back so I can give a educated and correct reply to these messages.



Thank you for your time!

What happens with a PSU over time?