Never worked for BigTech, so I'mm really not in my territory, but I wonder what is the purpose of all those interviews to get "the best of the best" and then let these things happen. What are the incentives for the management layer?
secondarily its an industrialization of software development. the hiring process is where they try define the labor as a replaceable component. grab the best cogs you can annually for the lowest price, run them in the machine for 2-4 years and swap most of them out before they get too expensive, or specialized or uppity.