I wouldn't say that the complexity is because of elitism. It's because the system needs to have certain incentives in place to function well. If we want to have a blockchain that works without users having to pay fees, we need to have at least two currencies. The system is also highly inflationary which means that there is also very big need for a price stable currency.

I just don't see how it would be possible to design a blockchain that could function as a backend for social media platform with only one currency. We need to have free transactions because users don't want to pay for posting, commenting and voting.

A blockchain with one currency would be certainly more simpler but if it means that system will fail in the long run, it's kinda useless to ponder about it.