> then at the end, the example from elm looks great, but i see lots of impure state being generated (browser, model) or am i missing something?

All functional programs (even if written in Haskel) have side effects - the CPU only has a certain amount of registers that can be used, for example, so any nontrivial program will be constantly overwriting them. That elm program however only exposes pure functions in user land, just like with a Haskel program