A death benefit paid to a named person doesn't go through probate. It doesn't wait on a court, it isn't part of the estate for distribution purposes, and in most states it's out of reach of the deceased person's general creditors. The claim gets filed, the carrier verifies, and the check goes out.
That's not a feature of life insurance being special. It's a feature of the beneficiary form. The policy is a contract that says pay this person, and the carrier follows the contract.
Which is exactly why the form is the whole thing. Name your estate as beneficiary and you've handed the money to probate on purpose. Leave the form blank and most contracts default to the estate, same result. Now the money sits in the court process for months, the creditors get a look at it, and the people you meant to help are waiting on a judge's calendar instead of a claims department.
Two other things come with the beneficiary form. Life insurance proceeds paid to a named person are generally income-tax-free to that person, which is separate from probate and often gets confused with it. And a per stirpes designation, which is a phrase your carrier will use, decides whether a deceased beneficiary's share goes to their children or gets split among the survivors. That one word changes who gets paid.
The other version of this failure is a form that's simply old. An ex-spouse who's still listed gets paid, and your will doesn't override it. A minor child named directly can't receive the money, so the court appoints someone to hold it, which is the probate delay you were trying to avoid. If a minor is in the picture, that's usually a trust or a named adult custodian instead.
None of that is legal advice and I'm not an attorney, so if the estate is complicated or there's a blended family involved, get an estate attorney on it. The five-minute version is in the beneficiary checkup, and what happens after the claim is filed is in how a claim actually gets paid.