It's also too late for antiviral drugs, though, FWIW. This drug needs to be taken within three days of symptom onset. By the time most people are hospitalized, the viral phase of illness is pretty much over.
I was referring to various antivirals, not just protease inhibitors. Plenty of patients are given monoclonal antibody infusions during hospitalization (see for example the former US president).
Monoclonal antibodies have to be administered in a clinical setting because they're administered by IV, but they also work best when administered early (diminishing returns after five days[0]), whereas most hospitalizations don't occur until the inflammatory phase of disease, in the second week. Remdesivir is/was the only antiviral being regularly given to patients with severe disease, probably out of a desire to ration it and only use it for people with the worst cases, but that's probably why it didn't really work very well, and is now mostly being abandoned[1].
The drugs that are most effective for hospitalized patients aren't antivirals, they're immune modulators: steroids like dexamethasone, and IL6 inhibitors like tocilizumab (which technically is a humanized monoclonal antibody, but not against COVID, and doesn't have any sort of antiviral mechanism of action).