In case this was addressed to me, just to clarify:

1. I did not suggest anything about romantic relationship, I meant any relationship and how hard it is to bond when we do not have much in common with the other person

2. by 'sketchy' I meant: someone who withholds about themselves. This was not a judgment but closeness in relationships also happens when people open up to one another. Otherwise the relationship is unbalanced at the very least.

Here there is no common interest and no personal sharing. This makes it hard to sustain a relationship or feel any satisfaction long-term.