It doesn't have to exist - I run next.js self hosted and it's arguably better than hosting on vercel (no cold starts, dedicated cpu, next to my api server/db).
I also self-host but it must be said that "no cold starts" and "next to my api server/db" are also supported by Vercel so that's not really a benefit
I also self-host but it must be said that "no cold starts" and "next to my api server/db" are also supported by Vercel so that's not really a benefit