I'm not so sure about that. I've read wikipedia articles about subjects I know well and found the language to be needlessly packed with jargon such that it could at least momentarily dazzle and confuse the inventor of the subject himself!

Rigorously precise language (e.g. "jargon") is almost never needed for a top-line description of a thing, and I think should be discouraged, in general. Yes, highly technical descriptions targeted toward professionals and academics in the field have their place in wikipedia, but ought to be relegated to periodic additions to the body of the article. That's just my opinion, of course, but as such I think its quite correct and admirably justified!

Feynman shared your opinion, so I’d say you’re in good company!

I agree in general, but in this case the extra information is sort of irrelevant - do we really need to say "in this flavivirus?" Something much better as an overall description might be "Remdesivir is an adenosine analogue that chain terminates RNA dependent rna synthesis, inhibiting viral replication" or something like that. Use the molecule name instead of a label, general instead of specific, and if you are talking about dengue in particular - why refer to it as a flavivirus? Who cares in this context? Just say "dengue" again instead of "this flavivirus." And, I don't think the drug has been empirically demonstrated to inhibit cytokine storms etc, that should qualify the description of the imputed mechanism of action by clarifying that it's the hypothesized effect the drug will have.