MyLegacy is more than that. You can write your funeral preferences (e.g. I had written a reminder that I had opted in for not just organ donation but whole body donation), and even account details and links to documents to help your spouse navigate things when you are gone. Really useful if you are the one managing most of your household's finances and bills.
Instructions needs to be passed on to your NOK in a timely manner. By the time a will is executed, it may have been months or even years, depending on how complex it is. In the meantime, all your money is locked up, and your trading accounts, brokerages, old insurance policies, crypto wallets or whatever may not even be known to your family.