Your project manager / business developer should ask itself that questions and find an answer - not your (dev)-job.

I'd been in the same situation but could change "projects" at an early stage. After 2 years of wasting 8 developers for a useless product (in my opinion) 9 devs out of 10 were laid off resulting in a freeze in the project and there's just one developer left... The reason was mismanagement and closed eyes/ears and finally the management asked developers to find a solution for missing USP ;-)

Like some other mentioned: Start looking for other job offers, keep calm at your current job & be prepared to switch to a new company or start negotiations for better conditions (depends on where you are and if there are other people willing to do your work).