I see a lot of this.
In one respect it's trivially true. There is no known effective treatment for the virus so the patient's immune system has to fight it, unaided.
But in one respect, it's almost certainly false. As you suggest, medics can intervene to prevent acute issues from overwhelming the body while the patient fights the virus, thus buying time - hence ventilators, draining the lungs of fluid, dialysis machines and the whole paraphernalia of ICU. However, those interventions must be timely (it's a matter of life and death), which is why ICUs in normal times have one nurse per patient.
However, I'm seeing reports that, in the midst of the COVID-19 surge, ICU nurses are having to monitor mutliple patients (maybe up to half a dozen) and, while I'm sure their efforts are heroic, it's hard to imagine some patients not falling through the cracks created when people are overstretched.
So it's hard to imagine the PM of the UK is being treated in an overstretched ICU in quite the same way as any other patient. As a minimum, I expect he has dedicated medical staff monitoring his condition and ready to act swiftly if it shows any sign of deteriorating. I make no judgement on whether this is right or wrong. Perhaps it is inevitable, but let's not pretend this virus eliminates all the special treatment that wealth and privilege secures.