Let's leave price aside.
IOTA promises to have found the holy grail - infinite scalability with zero transaction fees.
If that is truly so, then screw just the IoT usage, such a system should replace every imaginable form of value transaction known to humanity.
Unfortunately that is a claim I have seen no evidence to support. A transactional DAG still relies on a global state to ensure double spends can't happen, thus its still vertical in nature even though the architecture promotes horizontal scaling.
[...]
Would eliminating the global state be a step in the right direction ?
I came across another coin without fees(Raiblocks), that states having replaced "shared state" with "message passing" to be able to scale better.
Here some lines from the whitepaper :
RaiBlocks is designed to be a scalable and efficient distributed ledger platform. The design makes several significant improvements over alternatives giving a simple system that can process transactions in seconds making it a useful in a digital world.
To get these performance improvements we apply a critical optimization borrowed from concurrent computing where we replace shared state with message passing. This eliminates shared state contention greatly improving global throughput and lowering transaction time.
...
The ledger is the global set of accounts and
each account has its own chain. Only one entity can add a transaction to an account’s chain, the account owner.
This means each chain is not a shared data structure eliminating all contention when adding transactions to the ledger.The ANN is quite small :
https://bitcointalksearch.org/topic/annxrbcryptocurrencys-killer-app-raiblocks-micropayments-1381323
