First of all, it is necessary to separate the tasks that Spring Boot and Spring MVC solve.
- Spring Boot is a tool that allows you to create your application with minimal effort, be it a web project or anything else.
- Spring MVC is part of the Spring Framework, which is responsible for creating the mvc project.
Spring Boot is convenient for beginners in that with a simple configuration you can get a fully working application-pig, which can be expanded without any problems. You can use it, it just adds a lot of things that you do not need. If we talk about more or less serious products that you develop - this is not correct, and in the future, most likely, you will have to throw them out of the project.
Imho, Spring Boot is ideal for all kinds of prototypes, when you need to quickly make a working application to show / check / test / conduct research. In serious applications or with further development it will be easier and more correct to use the tools that you really need, and not everything in a row.