Django is suitable for server rendered applications. It can also support client side rendering/mobile via API interfaces. DRF is very popular for RESTful APIs.
The main points to consider are as follows:
If API is considered, the OpenAPI schema & UI logic should be consistent.
The separation of Server side code & UI design is via templates. It is not usually a single file, instead a hierarchical set of layouts.
Adding frontend library like React is not feasible. Primarily it won't be a single page application. But it is very popular & mature web framework. May not be suitable for NoSQL data bases.