The reasons include:

• Without a will, you have no say in who inherits your property. Everything is determined by state laws of intestate succession.
• No will also means you do not get to decide who manages your estate after you pass away. The court will appoint someone to do so and it may not be the same person you would have chosen.
• If you have minor children, then a will is where you nominate who their guardian should be. If you do not have a will, then the court appoints someone who might not be the same person you would have wanted.
• Without a will, it is impossible to plan for the impact of potential taxes on your estate.
• Wills generally make going through probate much faster than without one.
• If you want to leave anything behind for charity, then you need a will to do that.
• While you are visiting an estate planning attorney to get a will, the attorney might suggest even better options, such as trusts for your estate. You will not know if that is the right option for you, unless you go to the attorney.

If you believe you don't need a will, you are in a very rare position. You probably should go visit with an estate planning attorney and find out for sure.

Reference: The Bellingham Herald (March 22, 2018) "Here are seven reasons you want to protect your family with a last will and testament."