- Validations
- Translations
- Error and request logging and auditing
- Security (CQRS, CORS, CSRF)
- Permissions and a way to integrate it with your authentication (does supabase handle this? don't know)
- Email sending
- Background jobs
- Caching
- File uploading
- Rate limiting
- ...
Every time somebody suggests "just" Next.js, just "Remix", just "flask" or just [insert minimalist framework] I think they're either building something pretty trivial, or wasting a lot of time on rebuilding or integrating things you get for free with batteries included frameworks.