There’s one reason - from experience, it’s a lot easier to find a job if you are currently employed. So if you think you will likely be a target in round 2 or 3, the rational thing to do is to try to stay employed as long as possible and switch jobs quickly. Also, the severance tends to get worse with each round. I saw one job where round one got 3 months severance plus a week per year, with insurance, round 2 got a month, and round 3 got 2 weeks. I found new employment between rounds 2 and 3.

It seems like there are quite a few people here who have never experienced a tight labor market.