I wouldn’t say modern electronic music has a higher level of ‘sonic texture’ than orchestral music, or any music using traditional instruments. The difference is that in modern music ‘sonic texture’ is an explicit mode of “authorial expression.” The sonic textures creates by acoustic instruments are arguably richer, as they are capable of much more subtle modes of expression as playable instruments.
It’s just the case that the development of novel acoustics instruments is a whole separate craft, subject to the annoying vicissitudes of the sonic properties of physical matter. The instruments were developed over centuries.
As soon as instruments became electrified artists began using the ability to express themselves directly by manipulating the sounds themselves.
The sonic experimentation dominating modern pop music is entirely the result of the complete digitization of the sound generating chain.
I also think another factor is that digital synthesizers are woefully impoverished as instruments capable of expression through musical performance. Outside of the voice, modern pop is devoid of real-time musical expression. It’s become a non-real-time process, closer to writing, animation, the visual arts.
This forces the composer to rely on the native capacities of the instruments to express ideas, and the one that is completely unavailable in the acoustic realm is to chain the fundamental timbre of the instrument.
I’m a producer, recording engineer. The author of the original piece is missing that the only reasons a composer could imagine they were working primarily with the modes or melody, harmony, rhythm is that there is highly developed tradition of musicianship and instrument design to fill in the most fundamental aspect of music, which is the actual sound.
Edit: there is another huge factor in the decline of melody which is the product of two interrelated technology developments. The first is the use of loop based sequencing techniques for compositional work, and the second is that the random-access editing techniques made possible by modern digital audio workstations extended the loop based composition process to all sounds, including the voice.
Loops are basically short compositions. If you spend a lot of time in this mode or composition, your ideas will tend to be short. The actual mechanics of how the music is made disincline the composer from constructing both traditional harmony and melody.
The DAW has fundamentally disconnected music from the strict relationship with linear time that was inherent before the age of recording. To some extent musical notation allowed composers to work around this, but the end result was always an expression that had to have a thought out beginning, middle, and end.
I wrote an essay on this subject that I think is pretty good. https://dnamusiclabs.com/harmonic-distortion/daw-and-end-tim...