I spend hours with a family learning as much as I can about their loved one and each service is bespoke - not cut and paste like the religious ones.
This is harsh Vanilla - I'm a Reader and obviously offer religious services, for which I get my expenses only. No fee. I spend as much time with the family as they feel they need. Like yourself, I have, on occasions spent several hours , and made myself available by phone or e-mail as much as the bereaved family want.
I have learned to read between the lines when people are describing the deceased - sometimes it is not what is said, but what remains unsaid that is important - and sometimes you have to be careful not to stray into an area that might seem innocent, but in a particular family is filled with negative implications.
I don't cut and paste my funerals, and TBH nor do most of the priests I know.
However, priests, like celebrants vary greatly in the quality of the service they provide - what I do knows that I've never known a priest have more than two services in a day (maximum -and rarely those) whereas I have seen celebrants "cram them in" to put it crudely. However, priests generally don't have the time to offer that an independent celebrant has - especially in these days of combined parishes (our priest has three churches, and a Reader in each: the priest in the next parish has five - and no Readers or curates. It isn't just the number of services, it's the huge geographical areas many have to cover). This is no way excuses a poor service, but cut-and-paste, with personalisation, may be the only way some priests can manage it.
If you see my previous post, you'll see that I've said that I've been to some wonderful humanist funerals - funerals where the celebrant has captured the character of the deceased, and offered hope and joy for the future; and I've been to some bloody dreadful religious ones (my own dad's among them, where the priest got his name wrong).
It really all comes down to the individual leading the service.