Modern, but sane syntax (readable), good defaults (strong typing, null safety...), good-enough runtime performance, good APIs and tooling out of the box, cross-

Modern, but sane syntax (readable), good defaults (strong typing, null safety...), good-enough runtime performance, good APIs and tooling out of the box, cross-platform (also hot-reload on some, AOT). The list goes on, what specifics do you care about more?