You can cut 20% of a workforce through attrition, but it requires long term planning and shifting people to new roles. You don’t bleed projects over time but move people around after milestones.

Not every job is fungible so you may end doing some small scale hiring and let a few people go. But that’s normal and occurs outside of large scale layoffs.

Layoffs aren’t companies tossing risks, they’re companies offloading risk to their workforce.