Many designers think they have to do it all, especially when starting in the industry. Based on what I’ve discovered, it’s significantly better to narrow your focus down to what you love and excel at. Specialize in one area, then specialize in that area even more. For example, if your passion is to illustrate cats, then only focus on that and stop worrying about broadening your scope.
Specialization is the key to being truly indispensable as you develop real expertise in your domain. Next time a company or individual needs cat illustrations, you as the expert will be an invaluable hire that can command a much higher premium for that skillset.