Developers create the glue in code
Designers sometimes write the frontend code and sometime don't, but they will dictate what it should look like. Developers are associated with building the backend process and database elements. They dictate how the frontend has to communicate with the backend process to make the whole thing work. There is a heavy need to understand frameworks and libraries that best apply to the site being developed. HTML/CSS/JS skills are a given. Dealing with HTTP requests, REST APIs, and systems like NodeJS, Django, WordPress, Bootstrap, React, Vue, and Angular if your not so lucky. But now there's Svelte a compiled version of code done with Node.js. This turns your whole site into a JavaScript output with associated static files. This is the most efficient use of you source code and is a clear lead in web delvelopment. There is a strong need to document all code and there is nothing better than Git and the GitHub depository system. Code thesedays have many dependencies because there is no good reason to reinvent the wheel for all the processes needed to build a site. Module management is also a needed skill.
The spec'd version of CSS now includes Flex and Grid, which were separate products. Also libraries like Bootstrap can be short-circuited by excellent CSS techniqes using the same responsive approaches used in the libraries. Coding from spec and tailoring code can avoid verbose code. It all depends on when you jump into the stream. All the web building tools are changing all the time. It's not a bad idea to join a Bootcamp corriculum and get certified. Employers are suseptible to hiring from an interview where you demonstrate your web skills and move into a job without the expensive of a four year college.
Your motto should be "Go forth and Code."