With a few caveats, though they do tend to get fixed over time. For example, frame rate. Higher frame rate is better, the end, right? Wellll...

Latency and hitching are annoying to measure, so for a long time, they were pretty much ignored. That has improved and hopefully will continue to improve. There is the bufferbloat initiative, gaming magazines take frame time histograms now, input devices and screens commonly have their latency measured. But latency is still under-measured - for GPUs / GPU drivers, for all software, for games and particularly for websites.

Yeah, frame stutter is definitely one of the cases where somebody may end up targeting a proxy and that saying about targets happens as expected. A game which typically hits 50-60fps but has occasional half second stutters may not fix the stutters if your proxy was "time to render 100 frames" and you throw out outliers - since every stutter will be an outlier.