If you use a SQL database like Twitter/Medium/Reddit etc. there is no need for a blockchain or token or interaction fees. Having a blockchain is not a value add - to the contrary - its an expense, and as such it needs a real use case to be justified.
With USD its not viable to pay the long tail of content creation - you can't really wire someone $3. Its also a hassle to add support for new countries. And with FIAT payments you need to follow certain regulations and KYC requirements.
Ah yes the KYC and AML are a big deal for USD usage, though it sounds like it may not be long before platforms with cryptocurrencies must follow that as well...