Wood can also simply be left to itself, but one must be able to live with the consequences ... therefore, recommendations should always be taken with caution when they try to downplay the obvious disadvantage (durability!) of, for example, wooden windows.
A plastic or aluminum window must (!) actually never be painted and you do not endanger durability by omitting this maintenance either. Ultimately, it is also a question of money and taste. One does not need to choose wood and then want to paint it anthracite ...