It depends on the situation, and I think from what you've said, you're wrong here.
In the 1990s some of my friends left school at 16 and went into apprentices and jobs where they would have been on the "shop floor" equivalent as those in their early 20s. A number went on to marry those they worked with and most have stayed together. They were clearly love matches, with neither pressurising the other.
In today's culture 16 is a school child, with two years of education to go, and 22 a graduate, or been in work 4 years, there is a difference - same as you notice a difference in behaviour of the 4yo at preschool and a 4yo at school, because they are in different phases of life.
But in those days, no, they were very much the same level.
And it does depend on the relationship and personalities too. When I was at uni one of the girls got engaged to a 47yo. Some of us had parents the same age, and we did feel weird about it.
But again, it was a love match, and I can tell you who wore the trousers in that relationship, and she was very happy. And when we met him, they were well suited.
I think people need to remember that when we judge our parents and grandparents by the standards we see today, that our children and grandchildren will also be judging us by their standards - and probably finding us wanting too.