Does "Niche Specialization" eventually lead to a creative dead end for long-term freelancers?

[Btaliat]

When you are a freelancer focusing on just one niche, it does affect a lot, except in your intuition, you decide to be dynamic. Most people that are only focusing on taking just a particular niche always have a routine lifestyle as a freelancer. Apart from that, they are not always open to competition. What can you say about this? Do you think focusing on just a niche kills creativity of freelancers from exploring other niches?