Google is one of the earliest users of Linux. Microsoft, Amazon, Facebook all use Linux extensively as well. Only Netflix and Apple have a fixation on BSDs, but IIRC even Apple uses Linux internally for their servers.

Regarding Google, depends, they have been doing a GPL cleanup of Android, with Linux kernel being the last piece standing.

But fear not, Fuchsia already did its first deployment into production.

Just because they tolerate Linux’s usage of GPL2 does not mean they are neutral or positive toward GPL-licensed code. You mention Google, Chromium is not GPL-licensed nor do they allow GPL code in their tree. Their new kernel, Fuschia, is not GPL.

Linux is a great success story of the GPL, its ubiquity has forced corporations to tolerate it and reciprocally contribute back to the community.

Netflix seems OS agnostic. As far as I know, they run Linux in AWS, and FreeBSD for their CDN.