I concur. Ever since Elm 0.17 [1], when Evan removed event streams and standardized on The Elm Architecture, Elm seems to have lost its way. Just saying as an interested outsider.
[1] https://elm-lang.org/blog/farewell-to-frp
I presume it is a matter of perception: Elm is now perceived as a GUI toolkit rather than a language in its own right. Elm achieved simplicity and, ironically because of that, it is now plain easy to port its main ideas to other languages.
Since I don't know anything about Elm, I'm curious to see what about Sauron makes it more Elm-y than Yew.
JS/TS continue to dwarf everything else, but it's possible that Elm is the most widely used JS alternative at this point. (Hard to know definitely though!)
Cough. Cough. Clojurescript. Cough.