Sometimes the system sounds will be extremely loud for a fraction of a second (e.g. a new notification, or starting to type), then it goes back down to normal. This issue was reported last year, echoed by many, and hasn’t seen any fixes since the support team here simply didn’t understand our issue.
Here: https://discussions.apple.com/thread/252359501
And here:
https://discussions.apple.com/thread/252147152
how come the community specialists always misunderstood the problem that everyone was having? These are ABNORMAL behaviors that certainly cannot be fix via a software toggle.