Privacy on Bitcoin is slower, less convenient, and more expensive in tx fees and blockchain bloat than using Monero. It is also inferior privacy. Even if built on higher layers, there is always a core trade-off like loss of self custody or trustlessness for example, and it wont make Bitcoin as a whole fungible (or as fungible depending on your view).
Bitcoin mining is arguably more centralized because there are only a couple ASIC manufacturers and vulnerable because of massive targeteable mining farms. You can mine Monero on almost any general purpose consumer CPU. So it is also more inconspicuous.
Node count for both is roughly in the same ballpark