its pretty obvious that they don't actually like what they are doing.
My dad has been a mechanical engineer for almost 40 years and I struggle to think of anyone who enjoys their job as much as he does. Yet I have never once seen him do any personal "side projects" that are in any way related to his day job.
Many people truly believe in not doing anything related to their career/job outside of their workplace. They do something totally different instead. One might train for a marathon in her spare time, instead of learning the newest JS framework for example.
The side project concept is fairly unique to digital workers, especially software engineers simple because we can. Noone asks an accountant or a secretary for side projects.
My dad has been a mechanical engineer for almost 40 years and I struggle to think of anyone who enjoys their job as much as he does. Yet I have never once seen him do any personal "side projects" that are in any way related to his day job.