I was in this situation. Was told they were transitioning to a new stack, but that never happened. I gave it(wasted) 1 year. But, in retrospect, I waited too

I was in this situation. Was told they were transitioning to a new stack, but that never happened. I gave it(wasted) 1 year. But, in retrospect, I waited too long. If anything, after 3 months, I should have said: "My expertise is X. I want to work on it. I'd be happy to come back when you guys are actually doing X." I recommend interviewing at other places asap. Life's too short.