Is it just me? But every time I use a paradigm of global immutable state, almost always I run into edge cases where practically it falls apart either semantically (mental model explosion) or creates performance issues, whether they stem from architectural problems with the framework itself, or just the way computers operate.
its a trade off for sure
but my experience working with elm is that things just work almost always the first time
if they can bring that over, many will take that trade off
yes somethings are harder to express, but its subjective if its a bad thing given the correctness guarantees
i haven't firmly run into the perf ceiling myself, but yes it is obviously there for more interactive apps