Why? They weren’t laying people off because they were bad at programming. And in fact they were likely hiring so aggressively in the first place in part to keep top engineers away from competitors.
I worked at one of the companies in your list and will tell you from experience that they've moved on from the old and tried process for many types of interviews. My technical process with them back in 2019 was:
1. Tech phone-screen: work through a simple but relevant to your job exercise (no leetcode stuff and code didn't need to run... i.e. could be pseudo code).
2. Take-home exercise: where I got the chance to write quality code at peace and a technical design doc describing my process and findings. I'm certain the take-home made up for 80% of the decision.
3. On-site: chatted with both engineers and non-engineers about the exercise, and how I would've approached new hypothetical but real-life requirements.
Everything past the take-home exercise mostly revolved around that exercise. If let's say I had cheated the whole exercise, I guarantee you it would've been evident immediately for many reasons – including the fact that when I was working on the exercise I discovered and reported a bug in their own production software.
I worked at one, alongside others who like me had gone through their (in)famous process, and alongside others who had not (they came via acquisitions). There was no difference.
Similar has been said about Yahoo, MySpace, IBM and other companies that completely failed to innovate after adopting this erroneous line of reasoning.