DIY versus framework-based styling

Now that we have converted all our static CSS files into dynamic LESS scripts, we can definitely take the chance to replace the quick'n'dirty styling that we put together for demonstration purposes, only with something better. However, before doing that, we need to choose which of these we want to do:

1. Keep the Bootstrap framework that was shipped by our ASP.NET Core MVC with Angular template.
2. Replace it with another frontend framework such as Foundation, Pure, Skeleton, UIKit, and Materialize.
3. Remove it and also avoid any framework-based alternative, thus adopting a pure do-it-yourself approach.

The first two options share the same approach: leverage our styling on a consolidated environment used by thousands of developers; no matter which variant we'll choose, we'll end up walking on solid ground. The latter, however, is an entirely different pair of shoes. Anyone who is into CSS design is well aware of such a debate, which we can summarize in the following...