Better JIT, real threads (also Loom coming which is better than async/await or Promises), better standard library, better library ecosystem, better profilers, better debuggers, better metrics/monitoring for the VM, better portability.

It seems to me that the core server-side JS benefit is isomorphic code on browser and server which is probably useful if your team is small enough to have the same people working on both but for companies of the size I generally work for this is rarely the case beyond maybe small fixes I might do in JS/TS.

For me personally this can't offset the absolutely gigantic difference in quality between say JS/TS and Kotlin/Java.