I was a classic example, rushed into an early marriage at 17, made a mistake in who I chose and had to live with that bad choice for 28 years, as divorce was not an option. I eventually left both the marriage and the religion, as my health began to suffer and I just could not tolerate the mental pain. It's a shame it had to come to that, if I had been allowed to divorce I would have had a very different life. I was told that it was always better to preserve the marriage no matter what, which is probably the worst advice I ever got in my life. All I did was give my children a bad example of what marriage is, my children are now paying the price for that in their own lives. My suffering was for nothing.
The Watchtower model of early marriages and no divorce is a failure. Rather than resulting in happy marriages and intact families, it results in failed marriages, unhappy marriages and people getting disfellowshipped because they see no other way out. Choosing to stay unmarried is fine if that's what you want, but it shouldn't be a decision you make because your choices are so limited.
They solution is to stop using a book written thousands of years ago as a guide to morality. Sex outside of marriage is not some horrible thing and pretending it is just make young people rush into marriage, because young people have a natural and normal desire to have sex. They shouldn't be made to feel guilty for doing what people have done for thousands of years. Instead they should focus on how to have a healthy relationship, and how to be responsible about sex.
If people do make a mistake in choosing a marriage partner they should be allowed to divorce, not forced to stay no matter what, that is just a recipe for disaster.