I would like to point out a flaw in your reasoning or at least in the way you try to support your argument that antivirals may not work aswell as we'd like to (which btw is a pretty vague statement to begin with). You cite a study about neuraminidase inhibitors, which btw is largely concerned with prophylaxis, not treatment, while in your text you seem to be talking about antivirals as a treatment option.
In regards to treatment it states:"Pooled results showed that oseltamivir and zanamivir treatment alleviated the symptoms of influenza less than one day sooner. The time to return to normal activity could be reduced by one and half a days by oseltamivir and by less than half a day by zanamivir according to Burch et al."
Which to me sounds like a pretty good outconme, for example if we where to compare that to antibiotics and the time they need to alleviate symptoms.
If we where to talk about prophylaxis, I'd also argue that a 76% efficacy rate is, while obviously not perfect, nothing to sneeze at (pun intended): "In healthy adults, the seasonal prophylaxis against influenza showed a significant efficacy of 76% (95% CI 42–90) for oseltamivir"
However the far bigger issues is that you attempt to make an argument about antivirals in general, or antivirals in regards to Covid 19 treatment, none of which have much to do with the study you offer. Neuraminidase inhibitors are antivirals that use one out of 5 potential mechnisms to target the viral reproduction cycle (Attachment to a host cell, release of viral genes and possibly enzymes into the host cell, replication of viral components using host-cell machinery, assembly of viral components into complete viral particles, release of viral particles to infect new host cells).
This means you try to make an argument about all antivirals, only using data for a fifth of them and worse you only estimnate that particular antiviral drug against influenza while trying to make an argument about either all viruses or Covid. In the first case, you would be ignoring most viruses, in the second case you would be simple looking at the wrong one.
On a more opinion based/speculative note: I recognize that you do not have a background in either statistics or microbiology, however one of those would certainly be helpfull in attempting to analyze data about microbiology. The fact that you try to argue from what is clearly an economical background about the usefullness of antiviral drugs is not only misguided, because you clearly lack some topic specific knowledge, I personally also see a problem with an economical approach towards making decisions about human life and death.