The reasons why a web designer must have strong technical skills are:
The accessibility of HTML and CSS languages
First, the HTML and CSS languages are accessible and do not require a long learning cycle or extensive studies. Writing in HTML and CSS is not really coding since with these languages it is impossible to build logic. HTML is mostly a structure and CSS defines appearance and styles. Knowing how the Document Object Model (DOM) works and being able to intervene on a structural change is an essential and valuable skill for a web designer.
A Web designer must be able to control interactions.
There are many advantages to designing a user interface directly with code. The main reason is that the web designer takes into account the user experience in his work, indeed it is impossible to design for the web without taking into account this part at the risk of producing non-ergonomic models and difficult to use.
The programming work and the logic of the development (backend) are not the object of attention of a web designer, they are the programmers and the developers who take care of it. On the other hand, the colors, the spacing, the layout, the typography, the positioning and the zoning return directly to the web designer. The quality of the user experience of a product is recognized as a major reason for the success of a project. Developers or programmers do not care about the user experience and this is by no means their priority and even less their mission.
The user interface and the implementation of models.
We can compare a web user experience with the experience of using an application. More and more websites are actually application sites, that is to say, that they use real applications that run in web mode on hosted servers. For this reason, it must remain simple, accessible ergonomic and above all, does not require learning as with a conventional application. The interface with which users interact becomes more dynamic, contains animations, transitions, screens and regions that change content without the need to reload the page….
Formerly, web pages were flat documents while like the models for printing, but today, it is very difficult to create a model that corresponds to the identity of a product and that is faithful to a concept without the help of these languages.
Efficiency and time saving
It is obvious that a web designer who has mastered these languages, will be more efficient and will go faster in the design of a model using the appropriate languages. The divisions, zonings, interactions, as well as the business logic of the web requires the learning of these languages without forgetting the time saved since the model is ready for production and therefore does not require any other intervention, if not is a simple check before integration.
For a web designer, working with the code is like a classic graphic designer manipulating his drawing software.