Simple web CRUD WebFlux application: how can Netty be useful? - spring-boot

Question

I learned from here: What's the difference between Jetty and Netty?
Netty is not a server at all.
but from here: https://stackoverflow.com/a/57297055/10894456 I see it's the server.
Anyway I guess to run a web application there should be a server. So does Netty help to solve it? Or anyway need some kind of server ( Tomcat or Jetty or whatever)?
But from here: Don't spring-boot-starter-web and spring-boot-starter-webflux work together? I learned Netty is not compatible with Tomcat...
Clarify please, what is the easiest way to create a reactive WebFlux crud application? How can Netty helps? What would be the server in case of using Netty? How Netty is compatible with it?
Edit:
Ok, I see Netty is not a server by itself, need to write something like:
public class NettyServer {
private int port;
// constructor
public static void main(String[] args) throws Exception {
int port = args.length > 0
? Integer.parseInt(args[0]);
: 8080;
new NettyServer(port).run();
}
public void run() throws Exception {
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch)
throws Exception {
ch.pipeline().addLast(new RequestDecoder(),
new ResponseDataEncoder(),
new ProcessingHandler());
}
}).option(ChannelOption.SO_BACKLOG, 128)
.childOption(ChannelOption.SO_KEEPALIVE, true);
ChannelFuture f = b.bind(port).sync();
f.channel().closeFuture().sync();
} finally {
workerGroup.shutdownGracefully();
bossGroup.shutdownGracefully();
}
}
}
But I also believe literally noone do this when creating a simple WebFlux CRUD service. So still the issue: How can Netty helps? What would be the server in case of using Netty? How Netty is compatible with it?
Edit 2: after hours of browsing I realized: Netty - is not a server, it's just a framework using cahnnels/NIO2, but spring-boot-starter-reactor-netty offers non-blocking and backpressure-ready TCP/HTTP/UDP clients & servers based on Netty framework.
But can use spring-boot-starter-tomcat, spring-boot-starter-jetty, or spring-boot-starter-undertow instead in this manner:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
<exclusions>
<!-- Exclude the Netty dependency -->
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-reactor-netty</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- Use Jetty instead -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jetty</artifactId>
</dependency>
So just 2 concepts are confusing and mess each other: Netty and spring-boot-starter-reactor-netty