The following line:

https://github.com/spring-projects/spring-boot/blob/07a7ff473b6e97db6f00eb62f4f8beb2fb8da73b/spring-boot-project/spring-boot-docs/src/docs/asciidoc/web/servlet.adoc?plain=1#L45C1-L45C1

does say (specifically but without @EnableWebMvc) :

If you want to keep those Spring Boot MVC customizations and make more {spring-framework-docs}/web.html#mvc[MVC customizations] (interceptors, formatters, view controllers, and other features), you can add your own @Configuration class of type WebMvcConfigurer but without @EnableWebMvc.

IMO this should be made explicitly crystal clear as to why? Something along the lines of:

If you have a configuration with @EnableWebMvc in your Springboot application that basically instantiates the Spring WebMVC bean DelegatingWebMvcConfiguration which extends WebMvcConfigurationSupport and that trips/fails the @ConditionalOnMissingBean(WebMvcConfigurationSupport.class) annotation on WebMvcAutoConfiguration and it backs off.

I think many users read the section:

Enable MVC Configuration

which seems to tell them to turn on @EnableWebMvc.

I think @EnableWebMvc disabling the Spring Boots MVC autoconfiguration comes across as a confusing double negative to new users.

Once one understands what is going on it makes sense, but I got tripped by it and have seen issues filed and many SO entries.