When you meet someone in person, you have nonverbal cues as well as the actual qualities of the person right there in front of you to guide your judgment (the vibes, as it were).
The mindset you develop in this process can also cause you to think of a romantic partner not as a person but as someone who is easily interchangeable with someone else.
There is no way that an online personality test can predict how you, or your potential partners, will mature over time.
The same can be said for offline matchups as well, but the problem is in what the online sites claim to be able to do.
When their expectation doesn’t match reality, they are then more disappointed than they would be if they had met the person earlier on in the relationship.
This process is exacerbated by the tendency that people have to disguise their flaws either by bending the truth or lying outright about their age, their job, their background, or even their marital status.
The decision-making processes we go through when we’re examining online profiles are also different than those we use in offline situations.