Been a few years since I worked at Google as an SRE, but I did not find "There’s no incentive in big tech to write software with no bugs" to be particularly true. Perhaps because I was an SRE for a few of the of the older, intrinsic, core products. A lot of the pages we got were for things outside our control (e.g. some fiber optic cables got broken (we found out later), so we've got to drain some cluster because nothing's getting through there, or something's getting overloaded because it's the superbowl today, so throw more machines/memory at it, or other weird external things.) I don't remember a lot of pages due to outright bugs in the code... though it's been enough years now that I might have forgotten.