When Vercel switched everything to serverless, it all became pretty terrible. You need 3rd party services for simple things like DB connection pooling, websockets, cron jobs, simple queue, etc because those things aren’t compatible with serverless. Not to mention cold starts. Just a few weeks ago, I tried to build an API on Next.js+Vercel and get random timeouts due to cold start issues.
Vercel made it easier to build and deploy static websites. But really, why are you using Next.js for static websites? Wordpress works fine. Anything works fine. Serverless makes it drastically harder to build a full app with a back end.