Nobody fired 250,000 devs. A good chunk of these are sales, marketing and hr.
I think there is an assumption that all of the layoffs have been engineers or engineers, designers, and product people, but a huge chunk of them have been in support roles that are less needed without big hiring demands.
If companies are cutting travel and expense budgets, that means you can cut accounting staff. If you are largely not hiring, you can cut recruitment staff. Etc., etc., etc.