Tbf, to people saying that places like Relate plug in the gaps where the NHS fails, the NHS wouldn't offer therapy for the sorts of issues people go to Relate for.
The NHS exists to treat mental health problems such as depression, anxiety disorders, and severe mental illness. They don't offer relationship counselling or counselling around relationships, because that isn't a health problem.
People that would have gone to Relate can just find an accredited counsellor trained in couples therapy privately instead. Same rate.
We had a brilliant experience with a Relate counsellor, however it'll be a mixed bag as not every therapist is a good fit for every client, and there are bad apples of course.
The NHS doesn't offer bereavement counselling either (it offers treatment for depression, which may have been caused by a bereavement, sure, but not bereavement counselling itself) because that is a natural, normal, healthy human experience and not a mental health problem that needs to be treated.
I think a lot of people get things mixed up and presume the NHS is supposed to offer anything someone might want, free at the point of use, and it doesn't work like that.