Only way to 'not' be game over is if the network figures out someway to start punishing certain entities and singling them out to intentionally reduce their ROI and make them decentralize.  Namely by crippling them through increased difficulty intentionally.  Almost like breaking up monopolies or mega corporations.

Once manufacturers started large scale farming operations the writing started to get put on the wall.  And hence the increased focus on efficiency.  because if the market takes a tumble they can still keep their operational costs in check with ever increasingly efficient miners.  While the material cost of the miner has long since been paid off, hashnest selling mined coin etc.  It allows them to ride out the lows a lot easier then say someone with a S5 who is at half the efficiency level.  Never mind hashing power increase.

PS:  This is also starting to make me think a Proof of Share model vs Proof of Work model is going to be more important as time goes on.