How do you say the saying "Para o povo, não há cangalha que sirva." in English?
Solution 1:
I believe the equivalent in English would be "Some people are never happy".
Additionally, you could use "There's no pleasing some people", as suggested by Janus in the comments.
I can't find any equivalent phrase or idiom that expresses it more figuratively. It could be considered similar to "The grass is always greener on the other side of the fence", but that is more related to envy rather than continual complaining.