I think eventually there might be a performance problem with scaling, and yes each components seems to have a bit of boilerplate. But overall the pattern is very reusable and predictable, so if it really becomes the standard (instead of the experiment that it is now!) there could be compiler support for less boilerplate/ better performance.
For now I haven't seen enough people with actual experience using this architecture to really buy any complaints. I've seen more unintuitive things come around in Elm that seem weird (perhaps even wrong) at first, but by really trying it out, I've found that more of those things work really well!