I had to look it up again to check, but does this not fall under the dictionary definition of sophistry[1]? It seems especially appropriate to call it that given the 2nd definition of sophisticated[2] as something at a high degree of complexity, and "sophisticate"'s common root with "sophistry".
By making a complex argument, you deceive others into thinking that you have refuted another argument, when in fact you have not done so; the fallacy of your argument was hidden by it's complexity.
1. "the use of fallacious arguments, especially with the intention of deceiving." -- Oxford languages, via Google; https://www.google.com/search?q=sophistry (retrieved 2021-01-22)
2. "(of a machine, system, or technique) developed to a high degree of complexity." -- Same as [1], above.