Nice article and I totally agree! Even thought I studied CS in University, I considered myself as a sell-taught developer.
In the past few years, I experienced the same imposer syndrome and burnout you described in this article. It is quite terrifying.
Lots of people can build website, but only people with good DSA knowledge can build websites with FANG scale. For any useful applications, data modelling, data structures are the core. The rest can be easily replicated.
One thing for sure in computer science, no one knows everything. Change is the only constant.