Why is that exciting?
The traditional approach to building a web application is to separate the front end and the back end. Typically, the front end is built with a library like React, a framework like Angular, or even without any libraries or frameworks. The back end is then built in PHP or Java, on top, there are also additional frameworks for each programming language, like Symfony or Spring. Additionally, we need some kind of interface between the back end and the front end: An API. Usually, this is provided by the back-end team and has to be implemented or integrated into the front end by the front-end team. Even though there are ways to generate the mandatory code to consume said API - for example through the OpenAPI Generator(Given that it has been implemented considering OpenAPI standard) - the whole process is quite circumvented. There are multiple teams involved which leads to communication overhead, complexity, and therefore potential errors.
npx create-next-app@latest --typescript
What about data persistence?
Object-relational mapping tools ("ORM") facilitate the work with databases and have been around for "server-side" programming languages (e.g. Java or PHP) for quite some time. For larger applications, an appropriate ORM tool is an essential part of the technology stack to work with databases (querying data, updating database structure, versioning etc.).