My opinion.
I would say to a liar it is fun.
An old expression might apply here "believe nothing of what you hear and half of what you see".
When I read something I'm doing it for my enjoyment, and if I reach that goal I'm happy. Truth, lie or fantasy, it has absolutely no impact on my life beyond that enjoyment.
Movies, books, I'm sure no-one here watches only documentaries and reads only non-fiction. We do fiction for entertainment. Very few people start their story with "The following is the absolute truth", so we read it with the inherent understanding that it is possible fiction.
Disclaimer: I deplore and detest liars.