Well, there's a few ways of looking at it. But if the amount paid for electricity exceeds the amount of bitcoin earned, then most definitely, miners are "losing money" doing that (when computing in fiat terms). If a rig is efficient and power costs are low, then the miner is probably not losing money -- however, the depreciation cost for the CapEx investment may result in that operation losing money "on the books", even though they might be seeing positive cash flow, for instance.

But this happens, ... marginal miners get forced to either temporarily power down or permanently decommission and liquidate. Other miners that are well run (meaning had also invested in efficient rigs) will just keep on mining.