I'll also argue that after 10 years as a software engineer, if you're still just putting buttons on a page or waiting for next feature to show up on your queue, you're doing it wrong. Software engineering contains a large range of disciplines. You don't need to pick tech stacks, write code all day, or specialize in radar wheels.
Sometimes the job market doesn't provide people with fulfilling jobs and roles. They might not have any choice in doing it 'right' and just have 'wrong' as an option.
However, I have to agree somewhat with the assertion that software is getting more specialized. When I started out, the advice I repeatedly got was not to worry about what programming language you knew, because every job you would work with would expect you to learn whatever their tech stack was.
Given the author's interest in language and technical projects, I think they should add Sales Engineer & Solutions Engineer to the list.
Both are client facing sales / application setup roles... and Tech Evangelist roles as well.
Unless the author just wants to get away from IT in general, which is understandable.