iWF is not just persisting states, but also able invoking/executing states, searching for attributes(like unlimited database indexes), durable timer, resetting workflows etc.

Without Temporal/Cadence, it's 100+ harder to implement iWF. Even using SWF/Azure durable function is possible to build iWF, Cadence/Temporal is much more powerful than the other two(e.g. no reset workflow, search attributes)