I totally agree. In the old days the Church took care of this and people who had religious weddings had guidance from priests. I don't think that's appropriate for the majority of people today to get this in the church (I wouldn't welcome sexual or emotional guidance from a priest particularly) but I do think some sort of mentoring or support would be useful.
Most people nowadays go into marriage without the faintest idea of the legal or financial ramifications, let alone the emotional ones.
We seemed to have kept all the worst things about Church weddings (the morality, the froth, the subjugation of women) without any of the sensible pragmatic tools that marriage can provide. It's a recipe for disaster.
Of course the ideal would be to get this from your parents as well but the concept of marriage has changed so much in the past two generations that this is probably meaningless.
My mum got married in 1970 because, well, that was what you did. I don't suppose it occurred to her not to get married and as it turned out she didn't work so it was the right thing for her. She wasn't religious but she wouldn't have considered having children out of wedlock.
I got married in 2006 because it seemed like the thing to do. I turned out to be a total disaster for me financially because he thought my job was both to support him financially and to take care of all the domestic load. So I got the hell out of dodge. My mum didn't warn me about this because I suppose it didn't cross her mind to think about it.
The economic dynamics of relationships have changed so much in the past 50 years. In the 1970s it was almost impossible to consider that a marriage could be financially detrimental to a woman because in nine cases out of ten the man would support her. Nowadays that's far from clear cut. As more and more women are breadwinners, the case for marriage is far weaker and it only really makes sense today if you are sure you are going to stop work for a lengthy period of time. So what's the point of it really?
I hope that by the time my daughter (now 12) is old enough to consider this marriage will be more or less obsolete: it won't serve any financial purpose for an independent woman (it already doesn't) and the moral case for it has long since been put to bed. But clearly it is still an important insurance policy for women who want to remain at home.
The whole thing needs to be totally reframed and taken out of the sickening Disney miasma of white dresses, gold rings and table settings, for starters. This massively clouds people's judgement about what the goal of marriage is. Then we can have a proper informed discussion about whether it's worth it.