The other problem is that if you use this you only learn the specific DSL which isn't portable. But if you use and learn the basic technologies under it - HTML, CSS, and pure JS now that is something you can use elsewhere even if you throw Ruby away completely. And the knowledge of the basics is really really important and useful.
Anyways, what is a problem with writing good old .html.erb templates? I don't think there is any.
And for the reactivity thing - the most easiest and fastest(10 minutes at max to install and enable) is to just turn on Turbolinks[1] and include this little plugin[2][3] for persistent scroll position where you want. Now when when you click marked with `data-turbolinks-scroll = "false"` Turbolinks fetches the page, replaces the current page with it, and you are still at the same scroll position. No need for SPA or JS heavy FE or anything.
[1] https://github.com/turbolinks/turbolinks [2] https://medium.com/@kosovacsedad/how-to-turbolinks-5-scroll-... [3] https://gist.github.com/sedadkosovac/661d0fd369069cad010f164...