For now, at least, WordPress isn't going anywhere. With the aging technology of WordPress, it will become obsolete at some point in the future. So, you should start exploring more advanced alternatives. Keep in mind that WordPress, its themes and its plugins will be updated.
Please note that themes and plugins may become obsolete by themselves, due to lack of support. Be prepared before performing any theme upgrades or migrations. Try everything on a development site, if possible, or when there are few people on the site. This way, you can marginalize any potential problem before it becomes a huge problem.
So is web design a race in extinction? Cost-effective solutions that can be handled by non-tech-savvy people to create web designs without any help are quite compelling reasons why web designers can become obsolete. However, please don't draw any conclusions yet; let's consider the other side of the coin. In my experience as a WordPress developer, it's often easier to rebuild an old custom code site from scratch on WordPress than to dig into old code. Recent additions to the internal photo library, support for podcasts, and the option to save for later could indicate that WordPress is heading towards a one-stop shop for web content consumption.
However, if you need an original product and a highly customizable web presence, you'll do better with a custom website that uses WordPress as its engine. A lot of people will sell you WordPress because they have limited development knowledge, but they can search Google and hack WordPress. So we gave them a handful of other popular Oslo web agencies that had also abandoned WordPress for Craft CMS to close the deal.