Check how many buffers have been added (11102-112=~11000), that may be caused by many many HFN (high fanout net) in your synthesize netlist.
2 reasons I can imagine:
(1) poor qualify of synthesize netlist. (Maybe max_fanout, max_cap or WLM are not set correctly)
(2) poor floorplan causes a lot for detour in trial route, which increases estimated wireload and buffers are needed by the tool.
I would check the (1) first.
FYI.