If a side project _is_ recommended or advisable, then perhaps it should be about diversification. If my main job is software development, then my side project

If a side project _is_ recommended or advisable, then perhaps it should be about diversification. If my main job is software development, then my side project should be import/export. Branching into different areas will provide the growth and understanding of self that the author speaks about. Plus diversification will help me when AI takes over my coding job and I'm left jobless.