I can tell you exactly how I noticed it because it was on my workstation this reproduced originally.
I have a Ryzen 9 5950X CPU and it has a crazy fan ramp. Anytime a process maxes out the CPU it will be audible to me when I'm working. Now, to put this in perspective. It doesn't happen when I'm gaming. I can play Diablo 4 and Cyberpunk 2077 without this noticable fan noise but when setup.exe loses it, the fan noise is how I notice it. It will max out one core and I'm going to assume "never" complete. The longest I waited was 78 CPU minutes before killing the process. This would happen now and then but it would not prevent Chrome from successfully updating. So, it was bizarre to begin with.
I mean, it's only the installer. I know I only run it once per machine, usually right in the middle of installing all the rest of my usual utilities. It would be easy to miss that it's much too slow.
It's not like I have a good sense of what it does anyway, in addition to copying files for a fraction of a second.
Only one Chrome user successfully reached a developer in a position to do something about it. Who knows how many encountered it but didn't notice, and how many more noticed it but couldn't find a way to file a bug that would get noticed.
It's a good question. It could be that most people don't notice this things, those who don't don't report it, etc. Or maybe it only affects some people, but I can't think how that could be true. More mysteries
I'm running some monitoring that will tell me how setup.exe behaves on my machines. I tested it by forcing an update from Chrome. The private commit and private working set were 66.76 and 61.70 MiB, so no capping, but that makes sense because a user-initiated update isn't running at low priority, so we don't trigger background mode.
So, the only time the bug happens is for background updates that may be happening when the user isn't even present. And, since the CPU priority is low they won't harm responsiveness of foreground applications. But they will waste CPU time and electricity and battery life (if on battery). So, a silent waste.
