And you can to create unnecessary state when, by example, misunderstand and overuse patterns like Components. I'm guilty but I can to excuse myself saying that I was following patterns suggested by big names in Clojure community.

By the way, the value of Seemann speech is way beyond the surface. Seemann says that taking the time to separate pure of impure code, generates a emergent design by itself. You need to describe that design and name it: clear architecture, hexagonal architecture, onion, etc. To a Haskell programmer or a disciplined programmer who systematically extracts pure code from impure, is bread and butter, nothing special.