Massive layoff is not going to avert the sinking ship, maybe just delay it for a few years. The company may save money short term, but the best and brightest talents will be gone.
Those that didn't get impacted by the layoff will lose trust and faith in the company and will be looking to a better stabler company they can believe in. You will be left with the bottom pool.
Also, without 7nm program, what is in the product roadmap? Just derivatives? How can a foundry survive long term without a solid future product roadmap? Good luck, but you will need more than luck.