To reiterate what I posted in the other thread............It all depends upon the story being told in the song being sung. In some cases it's plainly senseless and adds nothing, in others it serves to wrap up the story.
Take Paul Metsers' song "Farewell to the Gold"- the last line of the first verse is...."I'll pack up, I'll make the break clean." That is a marvellous line to finish the song with if you leave off the chorus. Try it!
There are also some ballads where repeating the first verse really wraps things up ..... "Little Musgrave/Matty Groves" where it serves as a sort of repeated admonishment- 'now you know what can happen to you boys if you go to church to ogle the girls' sort of thing. I can imagine finishing "Alison Gross" with the first half of the first verse because there's a similar effect. Of course, talking about the ballads, it all depends upon which version of the particular ballad it is that you've chosen to sing.
Richard Thompson's "Withered and Died" is even written to end on the repeated first verse.
Come to think of it, I've written a song where, when I got to it, I realised that the only way to finish it was to repeat the first verse- but without the chorus.
To sum up, there are songs which are deliberately so written, there are songs where the repeat wraps up the story and there are the rest where it's obviously a quirk of the singer.
To be nasty for a moment...it sounds as though some people need to think a bit more about what they're actually singing.