If Bitcoin is not mined by any mining company, is it gonna die? Imagine the opposite. The fact that less mining of BTC will have an impact on the circulating supply and accordingly on the price. If you are exaggerating this news, you should also exaggerate the opposite.
No. No matter how many or how few miners are out there, the diff will always adjust to produce the same amount (12.5₿) every 10 minutes.
In fact this is expected, mining will become unprofitable and the hashrate will plummet, but not go to zero. The only reason this has not happened, is because the market decided bitcoin is worth more over time. Still, its slowly getting more and more unprofitable, so rather than a sudden situation change, its been going gradually.
Think of this: If bitcoin suddenly drops to $500, maybe 99% of miners will leave. But those few who remain, will keep it alive and the same number of bitcoin will keep being produced: New block every 10 minutes, 12.5₿ until next year, where it will be 6.25₿, then in 2024 3.125₿, slowly reducing the production as intended by the original design. This should stimulate a price increase, but the market price in fiat can't be controlled.
As fun as mining has been, miners should not think it will remain always profitable. I clearly remember 2015 back when the prize was 25₿ where everyone was whining how unprofitable it had become, only big whales could keep going on, etc.
Those miners who spend everything and live on the edge, have to cease the moment a little price fluctuation comes. Smart people should have been saving part of the income, not use/invest all until the inevitable day comes where its unprofitable. But then its no wonder people keep using PPS pools that in the long run earn less bitcoin than PPLNS. Managing themselves seems to be a problem.