The usage stats on GitHub are declining, for example. Devs are choosing Kotlin, Rust, and Go over Scala.

IMHO there are a bunch of reasons

* Scala 3 was a Python 3-esque disruptive event

* Perception as an overly-complex kitchen-sink inclusive language

* Kotlin took up the "better Java" mantle

* Rust became attractive to devs not committed to the JVM

* Go became less sucky

* SBT is disliked and Metals was buggy and unstable (and still slow)

* Suffers from the "we won't be able to find devs" problem where Kotlin, Rust and Go don't

* A bunch of community drama drove some devs away to Rust

I say this as someone using Scala 3 with ZIO effects system and Mill build tool and thinks it is fantastic.