Another fantastic post Ben!! Frankly, these illusions seem to be applicable to almost all professional role, not just software development.

I would add to this list "The illusion of self-worth" : the illusion where people associate a dis-proportionate amount of "grandeur" to the things they did as part of their job , things like how they prioritized family over work, how they showed kindness in letting someone take extra leaves, how they showed insight in recruiting an otherwise unfit person for a job-role, how they pulled an all-nighter into delivering some customer fixes , and start boasting about it on social media as if they are the next Mother Teresa or Albert Einstein. A typical cringefest mostly seen on Linkedin these days.