I am not sure why people are comparing a web framework with writing your own code in another programming language.

How many CVEs have you had reported yet against your custom code for probably the middleware you wrote to get a request with params available to use them (the params) in an SQL query?

Of course if you are good at this and have a lot of experience than even using an LMM I am sure your code is more than fine. But on average I think it is safe to say that any middleware or library code to deal with HTTP requests and make the information available for business logic generated by an LLM has probably a lot of bugs (some subtle some very visible).

For me the power of Rails is that if you do CRUD web apps it is battle tested and has a long history of giving you what you need for fast building business logic for that CRUD app. Is it the knowledge that is put into designing a web framework that works for 90% of the operations you need to write your custom business logic.