reactjs - Why MobX is less suitable for applications that have an append only domain model? -

the creator of mobx, michel westrate, said:

mobx suitable building app needs perform crud operations on state model. less suitable applications have append domain model.

if understood correctly, "append domain model" may refer apps consist of feeds/lists of data being added continuously (facebook example).

what mean "append domain model" , why isn't mobx suited it?

append domain models don't ever mutate state. append new state. strength of mobx in ability "watch" state , react when mutated. since aren't mutating state (only appending) lose out on lot of strength.

its still useful: if using mobx watch "size" or "count" or you'll reacting when values change state appended. that's not hard of problem concurrently watching 100's of state objects , reacting when of them change.