A few facts from history
I don’t agree with the OP’s 15 year timeline, nothing in history has resulted in a downturn that long. No disease outbreak in the last +300 years has lasted that long either.
Japan’s stock market hit its peak in the late 80s. So did their property market. So going on 30+ years and they’ve had ups and downs, but have never recovered and the trend is only going one way (let me spoil the surprise, Japan in negative rates for several months now)
Of course the outbreak will go away. We are already seeing better data showing the massive overreaction. But the virus was just the trigger device on this nuclear debt bomb. The fact that the global economy exploded how it did has nothing to do with the virus and was years in the making.
Remember negative rates started way before the virus, and so did the repo market meltdown as well as the complete reversal on tapering by the Fed.