Every now and again I read some sort of finger wagging article warning against the dangers of songs with few chords. "People are writing songs with fewer chords than they used to!" is the cry.1 The number of chords (or lack thereof) is deemed dumbing down what is on offer and that, of course, is terrible. Music doesn't really work this way, however. Its effect does not depend on the amount of ingredients, rather how they are used. This is a fear caused by confusing quantity with quality. I think the fear stems from a) the way art music developed in Europe (Western Classical music), b) children's songs, and c) our cultural drive to rate things and be associated with "the best."
The way music generally developed in Europe, the semantic meaning of harmony, and specifically harmonic change, grew to great complexity and works that were of great value to the culture were created. Simultaneously, many folk songs of simpler harmonic change were also created and are also still cherished, too. Western culture's value of individual achievement creates a sort of synecdoche for the wider cultural sense of achievement: Beethoven wrote great and harmonically complex music + Beethoven is a member of my culture = I am also great as a member of this culture, especially if I listen to Beethoven. It's like guilt-by-association, but in a "positive" sense — greatness-by-association. Of course, harmonic complexity only gets you so far: just ask people like Arnold Schoenberg or Ornette Coleman. Because we don't know who authored folk songs, they don't fit into this equation (The Great Man theory), either.
Children under 6, being inexperienced and less physically developed with their shorter vocal chords, need simpler songs to imitate in addition to the standard cultural fare, in order to be schooled in the ways of their culture: songs with a small pitch set and range and standard harmonic norms (no surprising pivots in a major 3rd relationship, for example). We absolutely need to maintain these songs as a culture. As one grows older and one gains more control over the voice and more experience in a wider variety of repertoire, it makes perfect sense that one would seek out pieces that are more complex, harmonically and otherwise. But that does not mean that harmonically simple pieces are "babyish."
Let's look at the drive to be associated with the best. This often manifests in music as ranking, best-of lists. But it begs the questions: Is the Beatles' song "Yesterday" a better song than "Paperback Writer" because it has more chords? (8 chords vs 2) What about "Eleanor Rigby?" Is it a babyish song because there are only two chords? Does it even make sense to rate Beatles' songs? What do we really gain from such an exercise? It can be interesting to discuss what makes something good, what qualities a piece generally regarded as "great" has, why we value the works from the past that we do. This kind of ranking of pieces against each other is a dead end, particularly if it comes down to simply counting harmonies. I am reminded of the following passage from Julio Cortázar's novel Hopscotch:
"The absolute,” La Maga was saying, kicking a pebble from puddle to puddle. “What is an absolute, Horacio?"
"Look,” Oliveira said, “it’s just that moment in which something attains its maximum depth, its maximum reach, its maximum sense, and becomes completely uninteresting."
Truly, the worst thing about saying that songs with fewer harmonies are somehow "less-than" is that it's the same colonial, hegemonic claptrap that people who should know better have been spewing for far too long. That somehow drone-based musics are not as good. That somehow rhythmically driven pieces only appeal to our base instincts. That you somehow become a better person the more "altered" chords you know. 2
From a pedagogical standpoint, using two chords help students not just learn how to play instruments, but also to start hearing the harmonic and melodic relationships of common practice musics. Having music with few ingredients helps with both the physical manipulation of an instrument and the ear training aspects of learning. But what's even better is the fact that we don't have to make up an entire repertoire. It exists already! There are "real" songs for children and adults that do their thing and work their musical magic with just two chords.
For example, this kind of thing: “Pitch has also decreased, with the number of chords and different melodies declining. Pitch content has also decreased, with the number of chords and different melodies declining as musicians today are less adventurous in moving from one chord or note to another, opting for well-trod paths by their predecessors.” https://theimaginativeconservative.org/2019/11/why-pop-music-is-so-bad-these-days-jon-henschen.html
We also have this example, in which the author bravely admits having had this kind of worldview and describes how they came to realize it was inaccurate and unhelpful:
Equally hackle-raising is the stance against harmonically complex music or music without a beat as somehow being a "vanity project" or, heaven forbid, all of Western Classical Music being lame, boring, lacking value. If you don't dig it, that is separate from its worth to exist in the first place. Or that all you have to do is slap a drum beat on it and then it’s instantly “better.”