And, from experience, you can enthuse and drive your staff at 100% for short periods - there needs to be a light at the end of a short tunnel to do so.
A good manager or team leader can drive 100% to about 80%, 100% of the time. After that, they are burnt out after a while. Usually spotted subtly by an increase in sick, or more obviously by underpants on head, Wibble etc.
The NHS are used to being at breaking point every winter, but get the breather they need in less busy months. The last 2 years, they have been beyond breaking point in the winter, and with further peaks throughout the year lessened only by full lockdowns. So its expected for many of them to be burned out, even if its their vocation. Those that aren't, are likely mentally weary as well.
Whilst I think the NHS is dreadfully inefficient, disorganised, irreparably broken and mostly useless, that's not to say that the low paid, front line staff are there to deal with those selfish individuals who are not prepared to take basic, simple steps to reduce the chances of them having to be admitted into hospitals with the chinky sniffle.