Took a buyout at a different Big Tech company earlier this year. It was offered to everyone under a given SVP (this other company tends to divide things up by business units).

In my experience, there were 3 main groups of people for whom these are attractive:

1) People who are close to retirement.

2) People who are leaving to become stay-at-home parents. So, basically retirement with more work.

3) People who are independently wealthy because they've been with the company forever and rocked the stock price appreciation. So, basically retirement with more money.

The amount of the buyout isn't really enough to move the needle for most other people because it usually doesn't include equity vesting. You're better off phoning it in and waiting for the layoff, because you get the same severance anyway but can continue to vest in peace until the axeman actually hits.

Folks who take the buyout do tend to skew heavily toward people with institutional knowledge, but it's also oftentimes folks who aren't really hungry and engaged with the company's current strategy. Basically folks who know a lot but don't work particularly hard. Particularly in times of big change, it likely does make sense for the company to get rid of these folks and rebuild the company in the image that they want it to be today.