The Twitter thread clearly points out that the electronics serve strictly as an intermediary layer between the paper test and the user. They just binarize the paper reading. This in turn gives a false psychological sense of security ("it's the computer that says it, not me"), without any credible benefit.
Why should I trust the people who calibrated the electronic device more than my own eyes?
More generally, why are people so eager to discount the reliability of their own senses? You have eyes and a mind which are the product of billions of years of evolutionary refinement. If you're not sure whether it's || or |+, pee again on a different test and compare; or wait a few days. If the lighting in your bathroom is bad, take the test in natural light or a better lit room.
My personal instinct is to rely first and foremost on my own mind and senses. It's of course important to defer to expert knowledge, but we need to use our critical thinking when deciding if something is the result of expert knowledge, or simply a marketing gimmick.