If you have ever developed a popular website in a microservice architecture, then most likely you have come across this case when, at first, your latency seems to increase. Then you check your dashboard and notice that the P90 latency has increased by 300ms in the past two weeks. It is very likely you will want to analyze the individual spans and see that one of your upstream dependencies, which belongs to another team, is slower. You could write them a ticket or even page them to fix the problem. They agree to it, but they also say that all is well on their end. Still, your service-level objective (SLO) is being violated. This is exactly the accountability gap that latency alone cannot solve. The page owner is the one who is responsible for the end-to-end latency of the page and may also have some dependencies which they do not have complete control over. However, the dependency owner does not have a formal agreement to maintain a specific latency profile per service, and quite fairly so. Everyone is technically following their own objectives while the customer experience is going down the drain.