I thought same. I fought for roll out in time, velocity and quality. Now I'm burned out. PM had his own agenda - introduced a men who, he was like 1/10x developer on senior position, promised to fire in a few month, have not happened in a year and a half, this destroyed velocity and as tech lead I was blamed. I stayed so long because our customers were awesome, could not leave them.

Managers are not friends. The moment I've said I'm leaving I become nothing. Time to learn.