I used hear and read about this - only on acoustic guitars, that they get sound better as they get played more.
If that is true, would it be the case for electric guitars too? Or it doesn't make sense?
The biggest problem with this whole question is that 'better' doesn't really mean anything.
Lets just say a pickup has become less magnetic and become mellower sounding over time, if you like a mellow sound you might think it's 'better' but if you like a more aggressive sound with a lot of bite, you might think it sounds 'worse' as it gets older.
I don't even know what you mean when you say 'better' and there's a good chance that my idea of 'better' isn't the same as yours.