Shockingly, 64 percent of the general 18-and-over population in the US did not have a will in 2016, according to Rocket Lawyer. This was highlighted in a recent New York Times article "Wills Can Avert Family Warfare, but Have Their Own Hidden Traps". Wills are especially important for younger people and those in close relationships but not legally married. Younger people stand a higher risk of accident and being incapacitated and not able to convey treatment or end-of-life wishes. Partners, not legally married may inherit nothing and have to move should their loved one die without a will. Without a health care proxy or advanced directive, a partner will generally have no say in the medical treatment of a loved one.
Even a simple Will is better than nothing so do it today. And, while you are at it, create an Advance Directive as well.