I think at least _part_ of the reason why is that it's just a whole lot less useful? There's tons and tons of applications for image and video and the automated analysis of it (for art, documentation or business purposes), whereas taste/smell capture and the analysis of it doesn't have that many useful use-cases (the article points at one of course, I'm not saying there's no use-case but much fewer). So we put a whole lot of effort and money into developing it, which didn't happen for smell.

Dog level smell is pretty useful, as evidenced, well, by actual dog usage.

OTOH maybe dogs are cheap enough not to create strong incentive for automation.