What happens when everything converges towards 0%?

In the euro zone we are seeing: Real potential growth and productivity gains that will come dangerously close to 0%; Very low inflation; Interest rates across all maturities close to 0%. So what happens when real growth, inflation and interest rates converge towards 0%? Real interest rates can no longer be made lower than real growth: monetary policy can no longer be made more expansionary; For the same reason, it becomes more difficult to use an expansionary fiscal policy than when real interest rates can be lower than real growth; There is no real wage flexibility, since lowering real wages relative to productivity requires lowering the nominal wage, which is difficult. In this economy, where everything converges towards 0%, it therefore becomes difficult to use all economic, monetary, fiscal and wage policies .