It's worth noting this post is a year old. I can't remember exactly if this was mentioned in the docs at that time, but it is now: https://nextjs.org/docs/app#how-can-i-set-cookies.
It's possible this post influenced us making the docs better last year.
RSC isn't a problem it is next implementation of it that is.
Understanding SSR,SSG,CSR etc is obvs where people get unstuck and that's fine but the api (use client, use server) and the arbitrary limitations on whatcan and cant be done serverside make this framework he'll to deal with
I think next.js is in danger of not existing. Openai moved to remix. I am moving to Astro many people I know are considering moving