If you have templates in your angular (or whatever framework) application, and you return HTML templates from your backend through a HTTP request/response, you are mixing up templates between the frontend and the backend.
Why not just leave the templating stuff either in the frontend (i would suggest that), or in the backend (pretty intransparent imo)?
And if you keep templates in the frontend, why not just respond with JSON for requests to the backend. You do not even have to implement a RESTful structure, but keeping templates on one side makes your code more transparent.
This will pay back when someone else has to cope with your code (or even you yourself are re-entering your own code after a while)!
If you do it right, you will have small components with small templates, and best of all, if your code is imba, someone who doesn't know coding languages will be able to understand your templates and your logic! So additionally, keep your functions/methods as small you can. You will eventually find out that maintaining, refactoring, reviewing, and adding features will be much easier compared to large functions/methods/classes and mixing up templating and logic between the frontend and the backend - and keep as much of the logic in the backend if your frontend needs to be more flexible (e.g. writing an android frontend or switching to a different frontend framework).
Philosophy, man :)
p.s.: you do not have to implement 100% clean code, because it is very expensive - especially if you have to motivate team members ;) but: you should find a good balance between an approach to cleaner code and what you have (maybe it is already pretty clean)
check the book if you can and let it enter your soul: https://de.wikipedia.org/wiki/Clean_Code