I don't actually buy this, no offense. It is true, however, that the aristocracy did influence music, but they didn't really influence "rules". The church and the tritone is probably on the only real strong-armed rule. I'd argue that the aristocracy went against the conventions and that's how we got "art" music, which has fallen out of favor in the centuries since, now that rich people have all kinds of other things to spend money on to flex on the peasants with. Most of that art music was intentionally composed differently from the peasant music because it had to be for the rich people to want to pay for it. They weren't going to pay for music that sounded like what all the commoners were playing, but if you look back on Beethoven, Mozart, and so on's most famous pieces of today — they are actually the ones that are closest to what normies of the day would've been listening to, which is quite similar to what we like about music today.
The "rules" most people are referring to here are usually rules of counterpoint or sometimes acceptable harmonies.
All of said rules had logical, at least for the time, reasons for being followed.
In composing music, people have generally followed whatever doctrine gave them the most-consistently-satisfying results. In the time of the greats, they were simply using what knowledge was available to them at the time, or at least widely understood.
This doctrine has expanded as our understanding of the physics of music and their effect on us has expanded. However, over the last 100 years, this doctrine has not changed very much despite massive leaps in the technology to understand it and ability to share information. This suggests that we are either at, or very near the borders of what tools can be utilized by a composer to create satisfying music — at least in the ears of 99% of people, it seems.
and if you go back through time, and you analyze the most enduring classical pieces, folk music, etc. you will find that they have a great number of consistencies.
Understanding what these consistencies are, and how to employ those same concepts in your own work, is where the "craft" comes from. That's why I'm a big advocate for learning that craft as much as we can; it gives you control over your music. You want to be in total control of what you're doing at all times. It makes composing music, and life in general, so much easier and fun.
Because if anyone was going to throw those "rules" to the wind and stumble upon some better, more reliable method of creating music that would advance the craft to a whole new level of understanding and open up a complete new set of musical devices for us to use — then it stands to reason that it would've happened by now, since tons of people are breaking convention all the time, just out of sheer ignorance.
With each passing year that it doesn't yield ground-breaking revelations, this point will become only more self-evident.
As long as we focus on writing GOOD music and trying to master the craft, that's all that matters. Our own uniqueness/identity will shine through as the result of our own quirks, favoritism, habits, etc. that rise organically if you let them.