A Minute on Characters being in their 40s in Romance Novels

A minute on characters being in their 40s. This is definitely a topic that hits close to home. I am always surprised at how 40+ characters are written in novels. Particularly in age-gap novels, I wouldn't say the portrayals are that realistic and sometimes that aren't flattering at all. Am I being over-sensitive? Liberties are often taken when writing, MCs are rarely that feisty in real life, nor are Villains that mean or dark. Is it ok, that being 40 in book often equates to lots of hardships and being at death's door? As ever, these are my personal opinions and are meant in good humour.