Your observations and questions are very astute and they get at the heart of this constant battle between more decentralization vs more centralization. On the one hand you get more security in the form of more people verifying and establishing consensus and on the other hand you get more scalability, efficiency, and speed. These are just the trade offs when it comes to service quality and security, but there are also political / governance trade offs as well as economic incentive trade offs that parallels these technology trade off decisions.

People look at decentralization and centralization in black and white ways, but the optimum mix is somewhere in between. I am finding that as the crypto ecosystem keeps evolving that we start adding things like second layer tokens which looks somewhat similar to the multi-layer system of the Federal Reserve Bank over private banks--to be sure there are still a lot of differences. I am just noticing a FEW similarities.

I have an outsider perspective on cryptocurrencies because I once worked at the Department of Labor as an economist studying inflation and so inflation in Cryptocurrencies is like watching a "natural experiment" happen in front of me. I am learning a lot. This is a great post!