Explain in the readme what really is a serverless deployment creation

From the readme, I learn that Kotless can automatically transform my standard spring boot backend into serverless endpoints.
But I don't really know what is and why use serverless endpoints instead of a normal spring boot .

It seems that each endpoint being a main() make the server actually launch when it is called. So we get the downside of having JVM startup time each time a route is called ?? This seems like a major downside and at what benefit ?
I probably lack knowledge, knowledge that would be great to introduce in the Readme. For now I don't know if Kotless can be useful to me, despite serverless being "en vogue".

Start with the repository README and review how Kotless describes transforming a Spring Boot backend into serverless endpoints. Clarify what serverless deployment creation means, how endpoint startup works, and the practical benefits and trade-offs compared with a normal Spring Boot deployment. Done means a newcomer can decide whether Kotless fits their use case.

Written by the indexing model from the issue text.