It's definitely reality but it would depend on your circumstances. Let's analyze this.
What's the purpose of underwear? For men, it's to help control the bits and bobs. Women have no bits and bobs.
So what's the purpose for women? Primarily it's to either appear sexy to whomever they are trying to attract, but the other reason is to keep their pants clean, generally because of poor hygiene associated with old age.
If they are trying to appeal sexually to others, and the pantyline fetish people are a small group, then it would make sense not to have pantylines. Which introduces the idea of the thong. What's the point? To appear not to have panties on but expecting to remove their pants at some point but not going so far as to not need panties, extreme teasers.
Seriously, if you know any women that would straight up tell you the truth, ask them.