Not really. Using joint ownership usually postpones probate. With most jointly owned assets, when one owner dies, full ownership does transfer to the surviving owner without probate. But if that owner dies without adding a new joint owner, or if both owners die at the same time, the asset must be probated before it can go to the heirs.
Watch out for other problems. When you add a co-owner, you lose control. Your chances of being named in a lawsuit and of losing the asset to a creditor are increased. There could be gift and/or income tax problems. And since a will does not control most jointly owned assets, you could disinherit your family.
With some assets, especially real estate, all owners must sign to sell or refinance. So if a co-owner becomes incapacitated, you could find yourself with a new “co-owner” — the court — even if the incapacitated owner if your spouse.