> Rails is so into agentic coding that they publish benchmarks of how effective different models are for building with rails

To each their own, but I think using Rails in the era of agents is probably a mistake. It has 2 big problems IMO.

(a) A ton of footguns that an agent can and will miss on occasion, and as we manually review less and less code, we will also miss it, and

(b) security on the web has become increasingly important due to hostile AI agents, and while rails has great secure conventions (see (a)), it's still easier to screw up something and not catch it until after it's deployed because there are simply less guardrails in place (dynamic types, no compile, slow tests, generally bad performance profile).