I hear a lot of people say this stuff in their 20s and early 30s when they have a lot of options.
When dating becomes superficial, that well starts drying up, or women are set in their ways, by late 30s and early 40s a lot of brehs on that #GMB wave start having second thoughts. I'm in that age group and I can't tell you how many of my friends are asking my wife to find someone for a LTR or they are saying "damn, I should have married so-and-so 7 years ago"
The big issue with marriage is it is either the best or worst decision you will ever make. Very little in-between unfortunately. The problem is people get married off what makes someone good to date or fukk and that isn't what keeps it long term. Values, goals, similar financial responsibility, desire to have children, etc. are important. Of course sexual compatibility is too but it is necessary, not sufficient.
If you are so worried about your assets, write a prenup. If she loves you and isn't a gold digger, she probably will agree if it is reciprocal.