How does PwC keep the best employees if Deloitte and EY both offer pension plans but PwC doesn’t?

I'm always baffled by the fact that despite PwC is one of the big 4s, it doesn't offer pension plan that EY and Deloitte offer to their employees. How does PwC keep their best people if they don't offer competitive compensation like their competitors? Is there anything that PwC does to compensate for the fact they don't offer the benefit? Does partner make higher salaries at PwC?