I highly recommend this blog post, which makes the same point among many (great) others: https://sled.rs/perf.html

> When we speak about comparative metrics, it is also important to avoid saying commonly misunderstood things like “workload A is 15% slower than workload B”. Instead of saying “faster” it is helpful to speak in terms of latency or throughput, because both may be used to describe “speed” but they are in direct opposition to each other. Speaking in terms of relative percentages is often misleading. What does A (90) is 10% lower than B (100) mean if we don’t know their actual values? Many people would think that B is 1.1 * A, but in this case, 1.1 * 90 = 99. It is generally better to describe comparative measurements in terms of ratios rather than relative percentages.

> The phrase workload A is 20% slower than workload B can be more clearly stated as workload A was measured to have a throughput of 4:5 that of workload B. Even though many people will see that and immediately translate it to “80%” in their heads, the chances of improperly reasoning about the difference are lower.