I think that's just how dating works

The really good part of this situation is that you are realizing that you aren't interested after a few weeks instead of spending months or years in a relationship you just aren't that into.
It sounds like what initially attracts you to a person is out of alignment with the things you want in a relationship.
Also, who is interested first, you or them? I used to find it easy to become interested in people who expressed interest in me.