Is it ok to meet with your advisor and discuss closing down the project?
My thoughts are:
1. It seemed like a high potential project
2. Over time you learned the return on investment may not be worth it
3. You need to focus on things that make forward direction in your PHD rather than expending any more time on this project.
4. This project can be shelved and others can take it on if interest returns in the future and/or you complete your PHD and have enough free time to return to it.
I think your advisor would appreciate your growth in this as a learning moment.
My thoughts are: 1. It seemed like a high potential project 2. Over time you learned the return on investment may not be worth it 3. You need to focus on things that make forward direction in your PHD rather than expending any more time on this project. 4. This project can be shelved and others can take it on if interest returns in the future and/or you complete your PHD and have enough free time to return to it.
I think your advisor would appreciate your growth in this as a learning moment.