I read the Bitmex research on who is funding Bitcoin, it is a very good thing for the space especially since the Bcash fork which create a huge divide in the space. I was just surprise that we don't have more miners supporting development of Bitcoin, I can only name Bitmain and Blockstream, this is not good, this just shows they are into the game for the money only
There is no fee that automatically allocated to Bitcoin developers from each block. Only Satoshi Nakamoto had a huge batch of Bitcoin from the genesis block and maybe some blocks later if he mined bitcoin years ago. For the rest developers, if they mined bitcoin, they have it, if not they don't receive anything from bitcoin network. I am not sure how Bitcoin developers receive their payments for their work, maybe indirectly from the network, from pools support them, or from donations, foundational funds.
Centralization of giant mining pools are always a bad risk for bitcoin network but still now that centralization has not yet caused replay attacks. We need more mining companies to keep the network more decentralized.