Not sure what Play Framework is doing at the top of the list, will most likely be many months before a Scala 3 supported version is released.

Same for Spark, DB libraries, Akka, etc. Basically everything with large dependency graphs that depend on macros or removed Scala 2 features (e.g. abstract type projections, arghhhh) will take significant time to port over to Scala 3.

What has had Scala 3 support from early on in the release cycle are the FP/Typelevel projects, which are obsessively maintained by the I'll-sleep-when-I'm-dead FP crowd.

Is Play Framework still used/developed? Haven't seen any progress from performance in the last years. Happy to get corrected, though.

It probably is still the most used framework, probably by quite a margin. Whilst I mostly use Http4s these days I would guess the majority of new projects still pick Play. I would say 60% but would not be surprised if the actual number is 95%.

The silent majority just need to chuck out another internal app quickly and Play is great for that.

It also looks like it is still heavily developed as 2.9 is released soon.

As for performance, shrug.