The true answer is yes and no. It is "yes" in the fact that both sets of cables carry a video signal from point A to point B. It is a resounding "no" when you consider the quality of that signal varies from one to the other.
While RCA cables are the norm, they were originally designed for audio signals rather than for video, and Characteristic Impedance (CI - the sum of the capacitive and inductive reactance with the signal) of an RCA plug is generally about 25 Ohms.
Component cables (including the RGB varients) carry a much improved 75 Ohm CI signal. One must be careful, however, as the cables with RCA plugs used on them are not. Cables with BNC plugs used on them are 75 ohm CI.
BNCs are a connector designed for video use (75 ohm CI). It is a cheap and HIGHLY reliable connector. BNCs come in crimp and solder varieties and are designed for specific cable dimensions (you match the cable to the plug type). The difference between one crimp BNC and another isn’t huge, especially in comparison with RCAs! They all work pretty well and other issues might be much more important to you like availability if coloured hoods (don’t underestimate the usefulness of coloured hoods on things like RGBHV cables). There are quite a few good varieties of BNCs. You can take your pick really. I would recommend Canare crimps. They are reliable, which is probably why most of major broadcasters around the world use them, although I am sure there are many other great varieties.
This may be more information than you wanted and most people could care less about a little bit of signal loss, but you did ask...