I worked at one of those places and helped rewrite components into Go ;) Sure, there were performance benefits but in my experience there was never a real business problem that Go solved that Python couldn’t.

All the people freaking out about performance didn’t realize that even in the Python days, half of our datacenters pretty much sat idle or severely underutilized. Computing is dirt cheap as long as you’re not renting a 15-year-old CPU from a Cloud Provider for 100x markup. The other thing is that engineers would frequently build things that were just wasteful or unnecessary, and sure, Go sped things up, but you could have changed the design instead of the language.