Layoffs = accelerated attrition of your best talent
Only assuming that the company does not have deadwood. In my experience: every single company over a certain size have people that are completely useless, only useful in very small area or got attitude/communication issues.
Layoffs are not always a bad thing. It all depends on how good management is recognizing a person's value to the core business. If they are terrible, it results in loss of knowledge, capability and destroyed morale. But if they know how to do layoffs right, it streamlines and revitalizes a company.