Are you always the one to plan things? Check on the other person? Take responsibilities and all that? If so, what concessions, if any, is your partner making? Where's the effort on their part?
Relationship and compromise are like two peas in a pod. A lack of effort is a universal sign of disinterest – and a relationship is no different.
A lack of effort from a partner is a universal sign of disinterest and you should not ignore it if you see the sign in a relationship.