No matter what discipline of design you are interested in, trends are always going to sway the direction of that particular industry at that time.
Typically, trends are a reaction to a previous design or style. These design trends can sway from colorful to monochrome, or minimalism to minimalism depending upon the general design in question. In many cases, a trend will come back more than once, if it worked in the past, someone will try to reinvent it for the present.
The design industry does not allow for a constant progression of ideas. The architecture industry is limited due to various regulations and limited new materials. Internet web design is limited through the media in which it is consumed. With time, these industries can develop and add new approaches and directions. Regarding the medium that is used, in the internet based realm, very little has changed over the years for the end user. While modern technology now allows for phones and other devices to access the web, the basic designs that are used could have been used decades ago.
Brutalist and minimalist trends are not going to help push the envelope forward, in fact, it just makes the design world come full circle. In fact, there were more complicated visuals on the web years ago thanks to Flash media.
One must then ask the question, why do trends even exist? They do nothing to move an industry further nor truly help the end user in either web or fashion designs. Trends simply exist as a visual interest for the consumers, clients, and designers.
Looking at web design for a moment, it is easy to see that websites have been stripped of all visual elements to form a stark, minimalist look. This is a current trend, and it does look good. However, this does nothing for the overall experience of the end user.
There are several sites who have bucked the trend and kept the same look for years. They know their design and style helps the user find what they are looking for. Instead of watching and giving in to trends, they have stayed true to their original look and theme.
One of the best examples of this would be the Drudge Report. It does not follow either a minimalist or brutalist trend in design. In fact, it has kept the exact same look for the past twenty years! Users of this site love the simplistic approach of the site. While other sites in the similar niche have breaking news alerts and flash reports, Drudge took it even further back and allowed its users to find what they were looking for.
Designers need to choose whether a trend is a concern they need to concentrate on or go in a direction that is designed for the main users. This typically depends on the industry and whether it is visual or user-oriented. Aspects such as logos and poster design will fall into these types of trends.
Whereas digital design should always follow the best interest of the end user. In the case of digital design, trends should actually be redundant and have almost no influence on the design decision.