Chemistry helps maintain relationships so long as all we are looking for are thrills. But marriage is not a thrill ride because it is unrealistic to expect every single day of the rest 30 to 50 years of life to be exhilaratingly exciting. This means of course Chemistry eventually breaks down.
The problem we have today is movies, novels, music all are characterizing romantic relationships as thrill rides, which in fact they are not, not if we are looking for stable relationships that last till death do us part.
My ex wife and I were compatible — I could be myself with her like I never had been with anyone ever. She also felt at ease with me. Yet we could not communicate effectively. We had chemistry but that was not the basis of our marriage — at least not from my side of the equation.
One important issue I realized ex post (after the fact, post divorce) was we lacked agreement as to the most important things in life. Not that we explicitly disagreed. We never explicitly tackled the question. All of our disagreements were implicit.
Marriage requires agreement on the most important things in life. Agreement on definitions of success.
So long as people get married without agreeing on the most important things such as,
will we judge our success by how much money we have or by our progress on worthy endeavors — work, spirituality, raising children, increase in relevant assets (assets can increase today yet not generate income until later in the future; people can make money today without creating any new assets — think for instance an employee earning salary but not getting better at anything) etc.?
So long as agreement on how success will be evaluated is lacking in marriages, divorce rates will remain high and perhaps experience significant increases over course of time.