I know but in general when you admit something like that, people also do expect like some preventive actions for the future.
All I can say is that companies for so long despised people changing jobs frequently as a lack of loyalty, etc. These major layoffs don't do anything else than confirm one thing: companies don't give a damn s** about you, if you happen to be in the wrong team or role or location.
They still mention 100+ jobs for many locations. Couldn't they ask these laid off people to find anything in there? These are people you spent so much time hiring, on boarding, ... and they even became "trustworthy" in a sense, they built relationships within a company. Now you'll hire new people, etc. And the history repeats itself.
Honestly, sometimes it's much better to work for smaller companies, at least you can have an argument with your boss, be pissed at someone. Here, you're just a number, bam, fired. But don't worry, we give you a severance package (for God's sake, at least that). This way of doing business should be outdated. I know in other fields it's much worse, but hell, these are companies setting the high bar in terms of "culture" etc, if they behave like that, what can you expect?
It's much harder to retain people, it can take months. But then don't come with "we're a people company BS".
He said "I take full responsibility for the decisions that led us here"
You can argue about the semantics of "responsibility" means, but i think in context he's basically saying "my bad". Nothing more nothing less.
If you look at the dictionary definition https://www.merriam-webster.com/dictionary/responsible this way of using it is consistent. "being the cause or explanation" is one of the definitions. Sure there are other meanings to the word, but this is the one that makes the most sense in context even if you wish he meant the other one.
Taking full responsibility here should have involved firing himself along the 12K. This is the norm in many cultures, resigning (or even killing yourself, sadly) when being responsible for a major failure.