I think what is missing here is that it doesn't have to be an either-or at the organizational level.

If you have a particular piece of the system that needs to be scaled, you can take that module out when it becomes necessary. You can alter your system such that you deploy the entire codebase but certain APIs are routed to certain boxes, and you can use batch processing patterns with a set of code outside the codebase.

You can have an admin application and a user application, and both of them are monoliths. They may or may not communication using the database or events or APIs.

However, you don't make this on the single bounded context guideline.