Of course we can truly achieve a state where no one feels trapped in a marriage if we remove these non-legal barriers to exit. If a couple has no children and no emotional investment in each other, then marriage will not be a trap. It will however not be much of anything else, either. There seems to not be much demand for emotionless, childless marriages.
The easier it is to leave a marriage, the less reason there is to invest in one. It turns out that for someone who does not want to be trapped in marriage, the best approach is to not get married. The cost of a good marriage is the risk of being trapped in a bad marriage.
In traditional marriage law both sides were protected inside the marriage. In modern marriage law no one is promised anything inside the marriage, and all practical commitments are for after the marriage. Instead of woman being trapped in marriage, men are trapped post-marriage.
The traditional approach to marriage did not guarantee anyone a happy marriage, but it did make marriage a worthwhile investment for both sides. Men and women knew that if they invested well in their relationship they would have a happy life together. They also knew that if they failed they would be trapped in a bad marriage. They had the positive incentive of love and happiness, as well as the negative incentive of strife, compelling them toinvest in the marriage. It is hardly a perfect system, but it works.
Today we have a system which tries to guarantee everyone that they will not be trapped in a bad marriage. They do not have the negative incentive of strife forcing them to get along, because if things sour they can leave. They instead have a counter-incentive restricting their investment. A heavy investment in their marriage does not guarantee any happiness, but it does mean that their risks are that much higher in case of divorce and post-divorce commitments.