It seems fairly obvious to me that the search for the perfect “soulmate” would likely be an excuse to divorce the imperfect person that most people are married to, and which we ourselves are.
I believe the person you marry becomes that “right one.”
Love is a choice both must make.
In my experience, there are no "soulmates". You have people who are willing to make an effort to make their spouse happy, and those who are not, and if you find somebody willing to make an effort for you, and you are willing to make an effort in return, then you will have a good life.
What is love? IMHO, it is the willingness to make an effort, or pay a price, for the happiness and well-being of another.