One Rails app used ~700MB of RAM at peak (live speed dating events with emails and heavy Hotwire/Turbo Streams use). I converted it to Loco with HTMX and the app now uses about 60MB at peak and benchmarks show 30x the traffic possible on the same hardware.
What more my CI/CD pipeline runs about 5 times faster including my entire test suite (TDD with hundreds of tests and BDD setup with about 60 scenarios running headless chrome). On a day to day while doing development my unit tests feel nearly instant.
Also Rust isn't as pretty on the eyes as Ruby but me downgrading my VPS server from 4GB to 2GB is something I benefit from when I'm away from my computer.
If you're a Rails developer nowadays I don't see the benefit of the framework anymore.
That being said it's an interesting effort that could become something nice with some community love
On my wishlist is batteries-included command-line setup support for database access using Diesel instead of SeaORM because I like formal types, and security tokens using PASETO instead of JWT because I like specific algorithms.