If you do not have an LPA and become unable to look after your affairs due to ill health, your family will have to apply for a Deputyship order to allow someone to help you. The application can take several months to process and is an expensive procedure, with court application, hearing fees, medical assessment fees and annual ongoing fees. In contrast the cost of executing an LPA is relatively low, with a registration fee of £82 and Will Creation fee of £200.
As well as being a difficult, expensive and time-consuming process to appoint a deputy, it can mean that for a time nobody is able to help you with your affairs. Possibly several months.
If you plan in advance and execute LPAs, you have the option of appointing more that one attorney and include reserves in case they are unable to act for you. You can talk things through in advance and explain your wishes.