There are trends in clothing, even in camouflage. There were early favorite patterns and many changes since. There will be more in the future.
Digital patterns were "cool" in the early 20th century and were adopted. Field service proved that they were not really anything special and the US Army has already moved on from them.
Military camouflage does not have to be "realistic" as in some hunting camouflages. They are not trying to fool a turkey 20 yards away. Military camouflage need to subdue and break up outlines at far greater distances. Natural details are ineffective at that range. But various colors and patterns can do the job effectively.
Unfortunately there will never be a good universal camo. It has to fit the terrain and season. Modern armies like the US will always have camo versions for forest, desert, mountains, winter, jungle, and other terrains.