Financial POA for my mother was put in place about nine years ago - my father was terminally ill, and he wanted to make sure my brother and I would be able to help my mother in the future if it became necessary.
He did it himself, and it wasn't too expensive.
Until last year, we didn't need to use it. I did a weekly online drop for Mum, and she had shared her bank details with me so that I could deal with any online banking that was necessary, but that was it.
However, last February she suddenly started declining rapidly, both medically and physically, culminating in her having to move into a care home later in the year, and her house having to be sold. This is when the POA has become invaluable. Without it, it would have been a lot more difficult even to organize her finances so that her care home fees can be paid.
Even with POA, some companies still make you jump through rings before you can use it with them (for example estate agents who insist on seeing the original POA, even though banks are happy to access it via a one-time code!), but it is still a lot easier than it would have been without the POA.
We didn't have the health and welfare POA until very recently. Luckily, we saw the way things were going and managed to get it signed and witnessed on a good day, while Mum had capacity to understand what she was signing.
That said, so far we haven't needed to use that particular POA, but sooner or later it might be needed.
The thing is, your children need to understand that POAs are not something that you can risk putting off until you need them. Health can change very quickly, and you could go overnight from being fit and healthy to no longer having having the mental capacity necessary for POAs to be made.