The core misunderstanding you have here is about the role of miners. The game theory that makes blockchains safe to use in a untrusted distributed fashion is t

The core misunderstanding you have here is about the role of miners. The game theory that makes blockchains safe to use in a untrusted distributed fashion is that anyone can just look at the chain and be convinced it's correct under its own logic. If most users are just relying on third parties to tell them about the blockchain then they can't be sure of its correctness. And that gives power to miners to collude between themselves and service providers to just change the consensus rules as they see fit, including in ways that are detrimental to the broader user. And why shouldn't people in developing countries run full nodes? Are you saying it's fine for them to be dependent on service providers in rich countries that can then control/surveil their activity?