Disposing of assets through beneficiary designations is popular today and seemingly easy to do. However, there are reasons to be careful when doing it.
It is possible and common today to dispose of many assets at death simply by filling out a beneficiary designation form. These assets will pass upon your death, to whomever is the designated beneficiary without becoming a part of the probate process.
The problem is that the financial institution holding the account wants it to be as simple as possible for it to find and distribute assets to the designated beneficiary. Ideally the account will pass to one individual who is clearly identified and whose locating information is available on the designation form. However, this is often far from ideal for the account holder who might want the assets in the account to be divided between multiple beneficiaries, whose locations might change over time. There are some other problems, such as potential tax differences between different types of beneficiaries.
The best thing you can do when designating beneficiaries, is to do so with the advice of an estate planning attorney to make sure that any designations fit with an overall estate plan. You should also make sure the financial institution understands and accepts the designations you want to make.
Reference: Wealth Management (April 23, 2018) "Designating a Beneficiary -- Not as Easy as it Looks."