Large companies overhire for a number of reasons during robust economic/growth conditions including having a sizeable ballast that can be jettisoned when encountering inclement economic weather.

Also necessary optics to show Wall Street that they are focused on cost and not just growth, as part of the quarterly virtue signalling exercise during quarterly reporting. Damned be the impact to staff morale, culture and overall longterm goodwill for the company.

Trick is to know what and how to cut, without impairing performance and growth trajectory, and ensuring that the cull is managed while minimising negative news fallout.

There are now whole teams in HR now dedicated to this function, to manage large purges beyond the usual annual performance reviews/PIP exercises for un-regretted attrition exercises.

With AI removing wholesale the need for human intervention/involvement in certain work functions (in talent management, Customer Support, etc), right-sizing becomes ever more important to stay competitive...