@Chewbecca But everyone should have an idea of who they would want to make decisions on their behalf if they are unable to. This doesn't necessarily have to be children, but should be someone. The alternative is that the decision making will be taken away and given to someone else without your consent (which you're unable to give). Depending on the nature of the loss of capacity, you might be very aware of this happening, but unable to express your opinion clearly.
Personally, I've dealt with both Deputyship and PoA. I can honestly say that the PoA route is far kinder. Before they became ill enough to lose capacity, I was able to chat to my PoA donor, establish and document exactly what her wishes were, understand her feelings about medical treatment (I held both types of PoA). So when she did finally lose capacity, I could advocate for her with her medical team, deal with the financials of her move to care so that happened seamlessly, make sure her home help was paid before she had to move, etc.
Compare that to deputyship, which has been a battle from the start. The application is still ongoing, so the elderly person has very limited access to money, debts are piling up which we can't pay because noone can access her accounts. This relative desperately wants to sell their house, but can't because they don't have capacity to contract an estate agent and noone can do it for them. The application process is extremely intrusive, asks for detailed information about finances, wills, executors, etc. It's created a hostile situation as the elderly person is deeply opposed to control being taken "against their will" but are unable to make decisions. They are just angry, which has triggered a deterioration in their cognitive state, so it's a horrible vicious circle.
I'd far rather have been able to have the kind, constructive conversations that the PoA enabled.....