The modern world is defined by globalization. New technologies have made it easier than ever before to interact with folks across the world. These changes have created a global economy that is becoming increasingly interconnected. For example, the headphones you buy might be made in Thailand, use parts from China, ship through a port in South Africa, and be designed in a downtown Manhattan office. The products we find in stores across the country are rarely made from start to finish in one place.
This is important because it shows that workers aren't expected to do everything by themselves anymore. Instead, they are being asked to specialize in a single part of the production process. Companies reason that this will lead to products being completed more efficiently. This type of specialization has become more and more prevalent in the economy as a whole.
I say all this to underscore the fact that businesses are starting to value specialists more than generalists. They want an employee who is one of the best at a certain task rather than someone who is pretty good at a lot of different things. Your question asked whether it's better to be an expert at one thing or a "Renaissance person". If by better you mean better for your career, then my vote is for being an expert.
However, that's not to say you should organize your life and your goals around your career. If you want to be a Renaissance person, be a Renaissance person. You can use your varied skillset to make connections between different categories of knowledge that other people wouldn't make. This can be very valuable, economically speaking, in its own way. Above all, I would prioritize choosing the path that makes you happy. Otherwise, none of the benefits that you would gain from either option would be worth it.