Yes, but any trust, at least as far as I am aware, forces the person executing (or whatever the word is) the trust, to surrender at least a little bit of their total control over the assets covered by the trust. Not everyone wants to do that. I would be one of those folks. I have actually considered putting many of my assets into a trust for my son, but anything can happen — you can have unforeseen expenses and/or life events, and you need your assets, but you can’t get to them, because they’re tied up.
I tend to agree with you. Pre-nups have an “ick factor” from the Catholic standpoint of the permanence and indissolubility of marriage, but this said, there are far worse ideas in the world than pre-nups. They only address issues of civil dissolution, not sacramental integrity — they’re legal agreements, not theological affirmations. A couple who civilly divorces still remains married in the eyes of the Church, and thus in the Eyes of God (Matthew 16:19).
I know we all adhere to the permanence and indissolubility of a sacramental marriage, but just being real, there is such a thing as original sin. Our culture presupposes that every couple approaching the Church for marriage is in love up to their eyeballs, and views their own union as something so strong, so formidable, that a hydrogen bomb couldn’t blast it apart. But then things happen. One of the spouses can get fat and ugly. One of the spouses can become devastatingly attracted to the hot little number (of either gender) at work that they see every day, and gradually (or not) there starts this little voice within one, “this is the person you’d really like to have, not your spouse”. Or problems can come out of the woodwork, perhaps hidden all along (even to the person who has the problem) — alcoholism, a drug habit that starts out innocently enough, sexual deviancy of this sort or that, the list goes on. True, the spiritual bond remains, the marriage remains valid, but things can deteriorate to the point where the couple is forced to live apart, and to seek a permanent resolution of property and child custody (assuming they have children) issues. When it gets to that tragic point, it might be a good thing to have something in place, if for no other reason than to protect against what a judge might decide. As I said above, you can determine your issues with surgical precision, but a judge will simply use a meat cleaver.