The same reason as any other, the mix of WLB, compensation and career growth. But notably the article isn't stating Meta will meet other offers, they may also beat other offers. Its merely saying they won't be compelled to offer in their upper range of compensation if they don't believe you have any leverage, i.e. why would they negotiate if they don't need to. Also unspoken is that both the lower and upper are still high -- I wouldn't be surprised if the lower is higher than a majority of other companies' median or even upper brackets.