The top player in the PC space, Lenovo, maintains about a 20% share. So Apple is not doing so badly at 10%. They are a top-5 computer manufacturer by share.
In the most recent financial data I could find, Lenovo reported total company revenue of almost $13 billion, and Apple reported Mac-only revenue of just over $5 billion. So again: not the leader but doing a lot more than just surviving in the PC space.