> I don’t think the canal theory ever gained much traction.
I'm not sure what you mean by traction. I wanted to show examples of scientific disagreement which made it to the popular press, to argue that it's been happening for a long time.
Using one of the sources mentioned at https://en.wikipedia.org/wiki/Martian_canals lists several I found this 1902 textbook which suggests it did have traction among astronomers for at least a couple of years, though not general acceptance. Quoting https://archive.org/details/manualofastronom00younrich/page/... :
] These new markings are faint and very difficult to see, and for several years there was a strong suspicion that he was misled by some illusion, — in respect to their "gemination," at least, — which is still ascribed, by some very high authorities, to astigmatism in the eye of the observer or bad focusing of his telescope. Still, the weight of evidence at present favors the reality of the phenomena which Schiaparelli describes. Many observers, both in Europe and the United States, have confirmed his results, and they are now generally accepted, although some of the best, armed with very powerful telescopes, still fail to see the canals as anything but the merest shading
I say "couple of years" because there are several editions of that textbook! In 1904 at https://archive.org/details/atextbookgenera05youngoog/page/3... :
] [Schiaparelli's] observations have since been confirmed and added to by various eminent astronomers in Europe and America, especially by Perrotin at Nice and Lowell in Arizona. But others, equally eminent and apparently under equally favorable conditions, fail to see the reported features.
While in 1888 at https://archive.org/details/textbookofgenera00youn/page/346/...
] "If there is not some fallacy in the observation, the problem as to the nature of these canals, and the cause of their gemination, it is a very important and perplexing one. It is hoped that at the next favorable opposition in 1892 it may find its solution."