The sentence starts with a direct quote, but ends with a sparse summation. The connection between these two may have been vague or even nonexistent except in the writer's mind.

My only guess is that the journalist truncated the quote or that it was implying a Node / JS backend.

They're not really alternatives in that one is frontend and one is backend, but they are alternatives in the sense of "here's new tech that hiring people might be aware of and are the defacto way to make web 2.0 (now 3.0) websites for clients".

I think the author was suggesting that many web apps are moving towards having a large frontend built in React/Vue. Therefore they don't need such a heavy framework as Rails on the backend and they can use something more lightweight to power their API.