This sounds quite a bit like Cloudflare Workers, and they have a comparison page - https://github.com/losfair/blueboat/wiki/Comparison-with-Clo....
- Cloudflare Workers now supports WebSocket.
- Cloudflare Workers now supports strongly-consistent storage / ACID transactions with Durable Objects.
- Cloudflare Workers is becoming open source, but not there yet (I am refactoring the code for this as we speak): https://twitter.com/KentonVarda/status/1523666343412654081
(Disclosure: I'm the tech lead for Cloudflare Workers.)
(Sorry. Rust wasn't ready yet when we started.)