Some fields have moved away from patents and almost purely to trade secrets. There are so many practical issues with patents now that in many cases they have negative value.

The downside of this is that companies who are using trade secrets instead of patents are no longer publishing either. Many areas of R&D that are primarily done outside of academia are becoming increasingly opaque because there is no up-to-date literature around the state-of-the-art.

Ironically, the situation that patents were meant to prevent is becoming common again now that patents are often effectively useless.