I like how Redux is a pretty simple distillation of some flux concepts... In the end, I think it comes down to application scale.  The &quot;new&quot; way of mutating models based on OO classes that tend to contain any given amount of logic tends to be much harder to reason with as you add features.  More features means a linear to exponential growth in complexity and risk of side effects.<p>With one-way workflows combined with immutable state, and idempotent components, it&#x27;s much easier to log&#x2F;replay&#x2F;test any given scenario.