In both threads you seem to be in search of these two extreme binaries that don't exist in the real music world. Complexity isn't as simple as being virtuosic, nor is simple is just melody and chords. Complexity is a variety of things; it can be a richness in harmonies, rhythm, counterpoint, or even concept. Simple music can have these things within them as well.
And whether or not you must write to some complex standard shouldn't be a goal. Complexity should arise from the desire to write it, not the internalized pressure to do so. It should be because you have something to say and more simple means isn't sufficient enough. Composers throughout history have written both complex music and simple music without compromising themselves. Most of the lieder from the 18th century and a lot of the piano music was simple and easy to play on purpose as they were intended for amateur players; yet some of them are held up with great esteem.
If you want to get a grasp on complexity and originality, listen to much more music. Listen to it and research the context in which is was made. Analyze it and understand its complexity, its simplicity, and its place in history. Approach the music with no assumptions. But most of all, don't use the music as a measuring stick for your own music. Instead, use it as a guide to grow as a composer in your own right and pace.