> and productivity are better in office (i.e., what they actually say in their announcements)

They had the exact opposite conclusions when they were pushing WFH. They also shut down comment threads and questions from internal employees asking for data backing up their more recent claims.

> Big tech companies are mature and no longer need to compete so heavily on brand/perks

If AWS starts losing employees at any serious rate, they will collapse. They already have a huge amount of products and services where the initial engineers left and where oncall/support load is absolutely brutal.