We're all aware that a huge portion of the busywork that makes a team successful is not actually reflected in their upwards-facing deliverables (increasing test coverage, improving infra, adopting new tools/methodologies, preemptive security patching, etc). Your actual high performers, if you have any, are doing all that stuff in addition to their regularly-scheduled duties.

If management weren't at least tacitly on board with this arrangement, your high performers would go work somewhere else. So my experience is that good managers don't tend to see this your way.