Another huge benefit is that it simplifies you application code immensely. Your store and models are simply vanilla JS since Mithril doesn't have reactivity, observables, etc. Mithril will simply redraw all the vdom whenever a user event happens or when its router/http client do something. You can also call m.redraw() if you need the UI to update if you for example receive something from a web socket.
Obviously with this approach the performance cannot be as good as something like Svelte or Inferno, but it's significantly faster than React.
https://krausest.github.io/js-framework-benchmark/current.ht...
Personally I use it with JSX since I can't stand the hyperscript notation.
It's certainly not for everyone and all use cases but I think it's totally valid for a good portion of front end work if you can handle a double edged knife.