I am kinda the same only I'm not clear how the author describes useful. Being useful to my team, my employer my clients is ok but a lot of my career has been building software for businesses I did not understand and sometimes actively disliked. I'm unofficially retired after 25+ years in industry and look back at a spotty record of building anything lasting and positive. I had plenty of great teams and received praise for being effective at delivery but honestly it feels hollow in retrospect.