Some do.
I've worked in the NHS for 30 years.
Clinical staff aren't exempt from piss-taking.
It was only 4 years ago that frontline staff were all told that pre-covid testing being available, any potential symptoms of covid meant 2 weeks off sick paid which also didn't count towards your sickness record.
And at that point, potential covid symptoms were basically anything that could be or look like cold/flu/respiratory related.
I was WFH by that point but knew numerous people who took advantage of that and were posting on FB from their gardens with their 2 weeks off.
It's important to note we were in an area with very, very low covid hospital rates so hospitals were virtually empty anyway. I'm not saying staff were abandoning very sick patients, there wasn't enough for staff to do on a normal shift.
I asked a colleague as a joke 'ooh you haven't taken your 2 weeks covid bonus holiday then?' and he laughed and said 'no, i'm waiting till it gets busy, there's hardly anything to do at work at the moment so it's already like a holiday'.
The shit the fan in my area towards winter. The months before that were a breeze for most staff working in the hospitals.
I was also receiving all the emails to staff saying there was an enormous amount of PPE (masks, gloves, aprons, not the full on PPE), toilet paper and paracetamol missing from wards and reminding everyone theft could not just result in job loss, and possible loss of professional registration but would be reported to the Police.
Funnily enough...all those things were in short supply for the public at that time and only clinical staff had access to paracetamol so...
It's only ever a small minority who do it and it in no way represents the majority of NHS staff but it happens. And with clinical staff too.