Another anecdote from my part. I graduated in roughly 2015. I've had 5 software eng jobs since then. Each one I've had at least 2 different managers in the average 2 years I spent in each. My latest role, however, I was at for 2.5 years and had 6(!) managers. I had originally intended to stay at that role longer term but it was obvious the constant managerial turnover was a negative for my career growth - so I hopped again.

I've not experienced a layoff, but I also think its extremely abnormal to be in a position for so long and only have one manager.