The cheap plywood support that the base attaches to has deteriorated and the screws don't hold on any longer to support the chair to the base.

The plywood the bracket connects to in the seat bottom has already split into a million pieces

a year before the arms tore thought the cheap plywood base.

The plywood broke and now the chair is unusable

I had to cut the vinyl to reach the problem but found the bracket is a large well engineered solid steel plate with plenty of surface area to handle the stresses and the wood is top quality plywood with no voids.

It's held together by one screw on each side into some particle board/cheap plywood maybe?

Plywood is not 100% foolproof

The back is supported ONLY by the arms, amd the mounts holding the arms in place are poorly secured to very weak plywood

This chair has fallen apart, the lumbar support doesn't exist anymore, and the arm is secure to the back of the chair by cheap plywood that has now separated

The cheap plywood support that the base attaches to has deteriorated and the screws don't hold on any longer to support the chair to the base.

The connectors in the back portion of the chair eventually break due to the back of the chair basically acting as a level arm (basic physics here) and over time break the plywood or other material inside the backing of the chair.

Assembling the chair wasn't a major hassle, but there were a few times when the instructions could have been clearer about certain parts (like which handle is R/L, it's not obvious looking at the handles themselves)