Content Management System
A content management system (CMS) is software that helps users create, manage, and modify content on a website without the need for technical knowledge. Basically, CMS lets you build a website without needing to write code from scratch (or even know how to code at all). CMS is used in most of the websites, but you could make a website without a CMS. Content Management System is used just for websites to manage content, and it also allows multiple contributors to create, edit, and publish.
source: https://kinsta.com/knowledgebase/content-management-system/
Coding a website by hand using HTML/CSS might be more complicated than making a website using content management system but it is the best choice if you would like to have the total control over what you want your website to look and feel like. If you have the technical knowledge, it is better to use HTML to create a website because everything you make in that website is going to look/feel exactly the way you want it to. If you don’t have the technical knowledge or want to create a website quickly, I would recommend using content management system. It is a lot more simple and faster than coding a website since everything is basically laid out for you, although the whole website might not look/feel the way you intend it to . I think the current best practice when it comes to making a website is probably CMS because of how simple and efficient it is. Best example of CMS is Wix because I have used it before when I didn’t know anything about web design and I felt like it was pretty simple and did what you wanted it to do.
I don’t think CMS would impact the web design industry that much since most of the CMS sites are used for simple websites. You will still need web developers to create a more complex website. If people want to create a simple website with not much functionalities in it than yes, CMS might take the jobs of web developers. This isn’t the case for bigger companies out there though because those companies will want something unique in their website that only a professional web developer has the capabilities of doing.