If there is no more love in the relationship it's just stupid to stay together.

If one partner in a relationship is not happy anymore, the other partner will also feel it and will also become unhappy.
If you stay together just for any artificial reason like 'it's sacred' or 'we committed long time ago' you will just make everybody involved unhappy.

So, if there is no chance anymore to save the relationship, quit it. It will help you and your partner in the long turn.

Don't waste time with the wrong partner. And if the partner is right or wrong can change over time as people also change over time.