Even ignoring that history loves to repeat itself, plenty of politics in all forms of media has aged excellently, and plenty of politics that haven't aged well are still insightful into the period of the piece.
"Everything is political" is the classic motte-and-bailey fallacy beloved by the most obnoxious politics pushers. The fact that it's impossible to remove all traces of politics from fiction does not excuse subjugating art to ideology. When people complain about "political" works they're complaining about works where the author appears to care more about how you vote than the story.
The dictionary definition of “politics” (as in, what the word actually means) would support the statement that “everything is political” to be at worst a smidge hyperbolic. No motte, no bailey, no rhetorical fallacy.
Thing is, most art has ideology, it’s the weirdo reactionaries that try to pretend otherwise.
The stance of "everything is political" itself is extremely tone deaf.
That's why old political writing is good - because the politics has been settled by now, most people won't argue 1984 was unfairly criticizing totalitarianism or Starship Troopers are too hard on fascism.
But new political writing is outrageous for half the people, because they disagree with it.