https://www.psychologytoday.com/blog/meet-catch-and-keep/201407/should-you-move-in-together-or-not
“So, in sum, what do we know about cohabitation? Is it a good idea?
As in most cases, the answer depends on the couple, but evidence points to a few patterns. First, we need to consider couples’ motivations for living together before marriage. Are they wanting to spend more time together, or are they unsure of the relationship and want to test it? Second, couples who cohabitate seem to be most successful when they’ve already committed to each other. Engaged couples who live together before marriage are not subject to the slippery slope of the inertia effect, which pushes two people who might otherwise not marry, to marry. The inertia effect may explain the heightened divorce rates associated with premarital cohabitation.”
Case to case basis, it would seem. I agree.