I'm not sure kotless is dead - but you'd have to ask JB folks about the priority list compared to Ktor etc... 😉).
But back to your question - several other JVM frameworks and libraries do support Serverless deployments - although not quite in the same way as Kotless tries to (ie. solving the plumbing issue for deployments).
For several client projects, I have successfully used http4k + Moshi + GraalVM + Pulumi for infra, but other JVM libs such as Spring and Micronaut also support Serverless deployments. My project experience is only with AWS, but http4k does support a total of 6 serverless platforms.