I’ve seen very close to bug free backends (more early on in development). But every frontend code base ever just always seems to have a long list of low impact bugs. Weird devices, a11y things, unanticipated screen widths, weird iOS safari quirks and so on.
Also I feel like if this was official policy, many managers would then just start classifying whatever they wanted done as a bug (and the line can be somewhat blurry anyway). So curious if that was an issue that needed dealing with.