Software Development is a very broad topic. Both parts of AI and Web development fall under “software development” as both are some forms of software. The “shared” parts that between the two are more on the topic of how you develop software in general, and less about what that software is or does. So stuff like understanding requirements, and project management are what you’d need to understand for both domains, or really any domains where you need to create software.
So you’d want to understand the problem you want to solve, how you can solve it, what kind of risks are involved, timelines required, features needed, etc, are all things you’d need to develop software regardless of what kind of software it is.
So if you want to focus on how to develop software in general, I’d actually look into books on the subject rather than courses, as it isn’t really something you “learn by doing”, rather its concepts you apply to “do stuff” (IE develop software). So you’d read about how to develop software using some methods, like Agile/waterfall and then apply it to some project your doing.
On the topic of AI, you can approach it from the theory standpoint, such as understanding the theory of deep learning and from a practical standpoint using freeCodeCamp.
Web development is taught primarily because its the most accessible domain, and still a competitive domain to find work in, as the web continues to grow and require people to work with it.