Blockchain lets us do some stuff now that was impossible before (single ownership of digital assets jumps out), but a big chunk of the economic benefit is going to come from reduced transaction costs.
Other cryptocoins including BTC, Ethereum, Litecoin or whatever do not have lower transaction cost than traditional currency. In fact I would argue that since public blockchain require mining transaction costs can never be that much lower than traditional currency.
If that middleman is in a big enough market with low barriers to entry and lots of competition, and is able to drive cost down with smart tech, it doesn't really matter to most users whether he exists or not.
Decentralised systems never promised low transaction costs. A private party running a database can do it cheaper and faster than a set of decentralised actors working for some incentive to establish the same database. That seems pretty much inevitable.
They did promise something else. Trustless-systems. But it hasn't been shown yet that consumers value this. (e.g. see our most valued companies like Facebook to which we routinely trust data (from secrets to nudes) we'd never, ever share with anyone else)
Blockchain's value proposition, as I've always interpreted it, isn't 'material' in the sense that transaction costs or speed are, but more based on the culture and the relationships of the 'value network'. i.e., the relationships aren't based on trust+laws, but on code+math. And it doesn't appear to me that the market values these relationships/culture, but it seems that the market does value the material aspects. hence there being no real blockchain users of blockchain applications. (except for the whole store of value thing, which drives basically all the price changes, but nobody envisioned the blockchain to solely be digital gold and nothing else).
I do not send money to my wife on bitcoin, I use venmo or bank accounts and it is free and immediate.