Pros
Most employees L3 and below are very cool and great to work with. If you are a toxic L4+ employee you can relax, even if you are demeaning to other employees, sexist, and incompetent at your job, Wayfair values you.
Cons
To start not everyone L4+ is bad, this is just a common theme that I've witnessed. Oftentimes leadership willfully condones or turns a blind eye to toxic, unscrupulous employees at the L4+ level (oftentimes men, and oftentimes because they both got ahead by politics instead of good old-fashioned hard work and ingenuity). These employees proceed to lie their way to the top - stealing credit for other people's work, not sharing relevant information, avoiding responsibility, blaming others for problems they caused, misrepresenting accomplishments, promising that another team will do something without ever informing that team etc. Many of them have a God complex and believe that they are untouchable in their ivory towers. They continue to free load, and everyday they hurt everyone around them and the company to benefit themselves and their status/position.