Assumed the free functions which belong to the same component have their own namespace, this is just a matter of taste. I am sure you won't find a hard, technical argument for or against those two approaches, they will both work and don't provide a huge difference in readability or maintainability.

So I would recomment you choose the variant which fits best to the programming style or "school of thought" of the overall system. If you prefer OO programming, use a class + single object. If you prefer hybrid style, or to use as few C++ language elements as required, use free functions. And if you don't have any preference, flip a coin.

Assumed the free functions which belong to the same component have their own namespace, this is just a matter of taste. I am sure you won't find a hard, technical argument for or against those two approaches, they will both work and don't provide a huge difference in readability or maintainability.

So I would recommend you choose the variant which fits best to the programming style or "school of thought" of the overall system. If you prefer OO programming, use a class + single object. If you prefer hybrid style, or to use as few C++ language elements as required, use free functions. And if you don't have any preference, flip a coin.