If I "walk along the train while riding it", as the author suggests, I can get from any station to any other station. Taking the tube from Moorgate to Barbican is not the same thing as walking underground, so this article is somewhat misleading.
79 karma · joined April 18, 2021
Secondly, there's this concept called "Independence Of Testing", which essentially states that the more independent the tester is from the code, the more likely they are to find defects. The opposite of that is also true, the less independend the tester is, e.g. if the tester is the developer, then the less likely they are to find defects in their own code. Read mode here (section 5.1.1): https://www.istqb.org/downloads/send/2-foundation-level-docu...
Lastly, this article is essentially saying that proper testing by QA people is useless, which not only I strongly disagree with but also is something that a terrible developer would say.